Oscar de la Renta stood at the head of the runway, his arm around a model in a caped pink evening coat. They looked as though they'd stepped from an 18th-century castle in Spain. The audience stood and shouted "Bravo."

Oscar de la Renta: the very name has a swirl to it. It stands for a certain type of elegance, a particular flair, a way of being more couturier than dress designer, more 1930s Noel Coward than 1980s Neil Simon. His best designs are for the ballroom, not the bar. You wouldn't expect nude models in his perfume advertisement. You would know Nancy Reagan is a model Oscar de la Renta client.

The suave man-about-the-world is as famous for the way he lives as for the way he makes his living. For almost two decades he and his wife ran such a glittering salon of people of power and posh as almost to eclipse his couturier salon. Franc,oise de la Renta died two years ago of cancer, but the pattern they cut for their life still shapes the fabric of his days.

At the first Hispanic Heritage fashion show recently at the Shoreham Hotel, the audience, mostly women, many Hispanic, honored de la Renta for more than his glittering costumes. They honored him as the rich cousin, the boy from a small Latin country who went on to become world-famous for his talent and luxurious life style, but never forgot whence he came.

Before his mid-knee wool jersey dresses and parrot-colored gloves paraded down the runway, pictures were flashed of the children's home and day-care center he founded and supports in Santo Domingo, Dominican Republic, and the foundling, Moses, he adopted.

The poor children of Santo Domingo are a far cry from de la Renta's Four Seasons hotel, a place so posh the sand in the elevator ashtrays is stamped with its insignia. For de la Renta, the patrone, the distance is bridged by noblesse oblige.

"Their mothers send them out to wash the car, to carry groceries and to beg, so they can't enroll in all-day schools. We give them reading and writing classes and one square meal, and they are free to work in the afternoon. We started seven years ago with 20 and now we have 350," he said.

"Moses was a premature baby found in a trash can when he was 2 days old. When he was up for adoption, I couldn't bear to let anyone else have him. For now he lives in my home in Santo Domingo. I go at least once a month so he won't forget me. He's 16 months now and just beginning to walk by himself. When he's 3 or so, I'll bring him to the United States."

His good works in Santo Domingo, as much as his successes in New York, which have won him three Coty awards, the fashion industry's highest accolade, brought him another award recently. At a dinner at the residence of the new Dominican ambassador, Eulogio Santaella, and his wife, Luati,de la Renta was presented with a huge piece of amber as an honor from the Dominican government.

De la Renta is such a Hispanic and couturier hero, that the recent benefit, which also spotlighted six other Hispanic designers, raised some $30,000 to be divided among the National Conference of Puerto Rican Women, the Mexican American Women's National Association and the National Association of Cuban American Women.

Though he is a citizen of the United States, "when I step off the plane in Santo Domingo, I am once again a citizen of the Dominican Republic," de la Renta said. "I have been accused of cultivating my accent."

This streak of sentiment, and his sensitivity to women, perhaps beginning with his six sisters, may help account for his multimillion-dollar business.

Nancy Reagan, for instance, is one of the thousands of women who think he understands the way they wants to look. De la Renta sends his new collections to her four times a year. "She is the best-dressed first lady we've ever had," he said. "She gives pride to the American designers."

Sydelle Shaw, manager of de la Renta's New York showroom and wife of his partner, Jerry Shaw, said, "We send down what we think Mrs. Reagan will like. She makes her selection and sends the rest back -- she has a good eye for herself. She's a perfect size 4. Of course, she was our customer before the White House."

But if de la Renta is a romantic, what he admires most is a disciplined perfection. He accepts no lapses of discipline from himself and has been accused of looking as precisely perfect as a show-window mannequin. He's too bald to speak of every hair being in place, but at 53 he's obviously acquired his patina by long years of polishing. At 9:30 a.m., in his hotel room on the day of his fashion show, he folded a yellow paisley handkerchief to go in the very fine tweed worsted fabric of his suit, over his pale blue shirt with the white collar. "Yes, of course it's my suit," he said. "I had it made for myself in Spain."

Having suits made in Spain was his early training in clothing design. "When I was 17, my father an insurance executive in Santo Domingo sent me to Madrid to study painting at the Academia de San Fernando.

"I had $125 a month -- a lot of money then. I ate and lived well. I shared an apartment with the young son of a grand Spanish family. At 19 he was already very fastidious. And every afternoon, I went to be fitted for a suit. I learned about fabrics, about fit, about clothes on those afternoons."

Though he was studying to be an abstract painter, de la Renta -- to help pay for all those suits -- began to do fashion illustrations for Balenciaga's couture house. He decided to give up painting in favor of clothes design and went on to work for Lanvin-Castillo in Paris, in 1963 for Elizabeth Arden in the United States and then for Jane Derby, which became his own firm.

In 1964, at a dinner in Paris for the duke and duchess of Windsor, he met the editor of French Vogue, Franc,oise de Langlade. They were married, according to one report, in 1967 on his lunch hour.

"Franc,oise had great discipline," he said. "A woman must be as disciplined about her appearance as a dancer, a writer or a painter. You must practice every day or lose it." He said that he misses his wife most in the New York apartment, where she reigned as a salon keeper par excellence.

Their life was often seen in full color in magazines, showing residences as elaborate and full of pattern and color as his designs. All facets of elegance -- a beautifully set table, a delicious dish, a perfectly arranged room, well-dressed men and women -- are, in their own way, art to de la Renta. People have speculated how he, by himself, would maintain those artistic standards in his life.

"Franc,oise was a wonderful housekeeper," he said. "She left me at the New York apartment a perfectly trained three-person staff from Santo Domingo. One has been with me 15 years. I try to keep things running, but now I realize how much time it takes. My biggest help is a telephone in the car. I have a driver so I spend the commuting time -- especially when we're caught in traffic -- talking to the butcher and the plumber and planning menus."

De la Renta has a caretaker and a couple in his Connecticut country home. "They are family. But I miss the conversations Franc,oise and I had." In Santo Domingo, he has a staff of six on his estate including a nanny for Moses. "Two are gardeners . . . life is slower there," he said.

In New York, despite missing Franc,oise and Moses, de la Renta surrounds himself with disciplined beauties. He loves women. In a December story under the headline "Oscar de l'Amour," the magazine W cited his recent appearances about town with women of fashion: Evangeline Bruce, Marella Agnelli, Marie-Helene de Rothschild.

De la Renta laughed. "Among the many wonderful things my wife left me were a great number of friends. She cultivated friendships. She worked at it. So when she died, everyone rallied around to take care of me. I have always hated to be by myself. I love people. Franc,oise was not like that. When I would go out of town for a few days, she adored to stay home and enjoy the house. She had been married twice, and divorced as a very young woman, and she said ours was the first real home she had had."

The business discipline for de la Renta comes from the other important people in his life: Jerry and Sydelle Shaw. At the Hispanic luncheon, when de la Renta was in the spotlight, Jerry Shaw talked about their business, estimated in 1980 at more than $200 million. With 80 product lines, including linens, sewing patterns, accessories and perfumes, it may even be higher now.

Shaw was with Jane Derby designs when he met de la Renta at Arden's. Shaw said: "I thought he was what Derby needed." Things were rocky at first because the workroom chief took de la Renta's designs and made them look just like the old things they'd always made, Shaw said. "Not till she left did he come into his own." The Shaw/de la Renta partnership is one of the longest running on Seventh Avenue -- about 20 years now. Syd Shaw has headed the showroom for 15 years.

The four-times-a-year fashion openings are as much society events as business ones. Stars such as Nancy Kissinger must be properly placed. "The seating is as critical as a dinner party," said Syd Shaw. "We all work on it. Though Franc,oise would place her friends."

The firm made its name with ball gowns, which used to account for 75 percent of the inventory. But now, Syd Shaw said, it's more evenly balanced. "Oscar is very good with suits. He was one of the first to put color with daytime suits and to use mixtures of colors. Now people think it's all right because he does it."

De la Renta himself thinks that his time has come again. "The mood of fashion today is more feminine. In the 1970s, women thought they had to dress like men to be heard in the board room. But now, they've learned they can still make their point while wearing feminine clothes. And feminine clothes are what I do best."

In Santo Domingo, there's a 14-month-old in a de la Renta sailor suit, waiting to be taught all about the discipline of perfection. But for now, de la Renta is content to watch Moses crawl in the sand.