Texas socialite Joanne Herring Davis swished into last night's party for visiting British nobility wearing a rather revealing black lace form-fitting gown, and let's just say the view from the balcony was breathtaking.

"I must go get Frank," said Jayne Ikard. "He doesn't know what he's missing."

"It's an interesting vantage point for visiting royalty," said a high-level White house official glaring down from the railing.

"She looks a lot like Zsa Zsa Gabor only a little younger," said Michael Herbert, one of the visiting Britons.

Not since Ronald Reagan's first inaugural has Washington seen so much mink, money and glitz.

This time it's for Prince Charles and Princess Diana, who are nine days away from taking this city by hurricane. Last night was an awesome dress rehearsal.

At a party given by Ritz-Carlton owner John Coleman at the hotel, the closest thing America has to aristocracy turned out in droves to pay homage to genuine dukes and duchesses and lords and ladies. It was a black-tie dinner to honor the owners of the Magnificent Seven houses, all of them lenders to the "Treasure Houses of Britain" exhibit at the National Gallery of Art. The exhibit, which contains art, tapestries, jewels and other objects from 200 British country homes, is the reason for Charles and Diana's three-day visit, which begins Nov. 9.

Under any other circumstances last night's party might have qualified for A List status. It was an impressive cross-section of international society, power and wealth: Jerry Zipkin and Caspar Weinberger, Leonore Annenberg and Henry Ford II, Pamela Harriman and Mary Lasker.

But early on, the royal visit planners let out the word that guest lists were being carefully coordinated to avoid duplication at what seems to be an overwhelming two weeks of revelry. Or, putting it another way, the hard cold social facts suggest that many of those invited to Coleman's dinner last night might not be putting on silks and satins to meet Charles and Diana at the White House next week.

Nonetheless, this crowd was just loving it.

"It's so bad that it's wonderful," said one guest, who didn't wish to be identified. "I kept saying this has got to be the worst party I've ever been to and it's so much fun I can't stand it. I have been in hysterics on the dance floor. I mean, there's Jerry Zipkin . . ."

"No, no I don't want to get into it," said Zipkin, running away from a reporter who hadn't asked him anything.

"I'm just so exhausted," said Chicagoan Bonny Swearingen of Standard Oil of Indiana wealth. "I went to bed at midnight because Richard Nixon was in Chicago last night for a dinner . . . and then I had to get up at 5:30 this morning to fly to Washington for Mrs. Reagan's lunch today. Goodness, if you're a name dropper I certainly had a lot of names in that remark."

Swearingen was wearing a green silk Ungaro that matched her emerald and diamond necklace. Perfectly. "It wasn't an accident," she said. "I looked hard to find this color. It's so vibrant. Did you see my bustle? I look for this color wherever I go."

"Oh really?" said pianist Peter Duchin. "If I see it for you somewhere I'll buy it for you."

"Oh would you, Peter, darling?" she gushed. "How wonderful!"

Up walked Charles Churchill, and greeted Duchin like a long-lost brother.

"Oh, are you one of those visting Brits?" joked Duchin.

When Churchill left, Duchin was asked whether Charles was related to Winston.

"Distant cousins," said Duchin, with the tone of a seasoned observer of such matters. And then with the perfectly timed pause of a deadpan delivery, he added: "But he'd like to be closer."

White House counselor Fred Fielding is a veteran at this royalty stuff. This summer he was a guest of U.S. Ambassador Charles Price at an embassy party in Britain. There, he told a reporter last night, he danced with Princess Diana.

"You never told me that," said his wife Maria.

"I did too," he said. "You just weren't listening."

Chief of Protocol Selwa Roosevelt was reluctant to divulge too much information about the forthcoming royal visit. "This is strictly a British Embassy call," she said. "It's their protocol. I mean, I'm going to have to call the British Embassy this week to find out if she's wearing a hat when she arrives so I know if I should wear one. I don't have to wear a hat, but if she is . . ."

Joanne Herring Davis said she and her husband Lloyd just flew in for the night.

"You see, we're newlyweds and there have just been all these parties for us," she drawled. She was wearing diamond earrings that looked like little chandeliers.

The evening's trappings were the stuff public relations executives' dreams are made of. The fancy menu included pumpkin soup served in a hollowed acorn squash, stuffed veal and cranberry apple brown betty. And announcing everybody was the George Brett of toastmasters, Britain's Ivor Spencer.

His introductions for the toasts were from another world.

"Your Excellencies, Secretaries, Mr. Mayor, Your Graces, My Lords, Ladies and Gentlemen . . . Pray silence for The Honorable Caspar Weinberger, the secretary of defense, the most distinguished guest of honor."

Weinberger, the ranking American guest, then lifted his champagne glass to the queen.

Later he said:"I must say it's a lot better introduction than I usually get. Usually it's 'Go on with your testimony.' It was my shortest, most successful speech."

Commerce Secretary Malcolm Baldrige will be included in next week's festivities even though he was a guest last night.

"I'm going to the dinner at the British Embassy," he said. "I was supposed to go to a rodeo but that got changed so now I can go to the dinner."

And what would he have done if the rodeo had not been changed?

"I'd rather not say," he smiled. "And you can quote me on that."