It takes more than Ronald McDonald and secret sauce to hawk hamburgers sometimes.

To beef up a foundering McDonald's restaurant in this city's financial district, store supervisor Manny Diaz hired a courtly white-haired doorman with top hat, white gloves and brass taxi whistle and chain.

Doorman Gale Miller bends and bows like some amateur Marcel Marceau, gesturing to surprise customers to come inside.

The food chain at 441 Pine St., just across the street from the Bank of America's world headquarters, competes with the brown baggers, popular sandwich-shops and a new Burger King around the corner.

The four-year-old McDonald's which had been a problem outlet since it began, was taken over in January by Eugene P. Gonzales, as licensee, who put Diaz in charge.

Diaz says it cost about $1,000 a month to keep the gracious doorman, but he already pays for himself: Revenues have increased by between 10 percent and 12 percent. "We're the only McDonald's in the world with a doorman," boasted Diaz, 34. "It works."

He credits the doorman, better service, greater friendliness and flyers promoting McDonald's with the improved sales. On an average weekday, he sells 300 pounds of company meat to the mostly serious-minded, diet-conscious adult eaters.

The restaurant, with its brass railings, wooden tables and paneling and tile floors, with only one Ronald McDonald -- a bulbous statue that blows up balloons -- now has annual revenues of "close to $1 million," Diaz says. That's still 20 percent short of expectations, a situation he believes will be remedied within the year.

Miller, who used to play the violin and sing in organ bars and who writes "lyrics that fit into any song," greets customers with a "hi ya," and a "good morning," and a twinkle to his pixish blue eyes. A one-time taxi driver, Miller believes that the McDonald's front door is his stage and the pedestrians his sidewalk audience. He kisses "the girls," hands out red carnations occasionally, and adds a touch of class to the fast-food restaurant. c

"When they gave me the top hat, I thought it would hide my appearance," says Miller. "So I put on a better personality to bring out the glamour and style."

He takes his role seriously: "You have to understand your public, and they have to understand you. You don't want to be too pushy.

"It's unusual for a person to open a door. I'm not used to it," said an otherwise delighted Cathy Long, carrying her morning's Egg McMuffin. She planned to return at lunch time "for my Quarter Pounder with cheese and french fries."

Her thinner friend, Tania Verduzzo, who is "not a lunch eater," said, "He's real sincere about it. I didn't expect the kiss and it didn't offend me."

"Far-out," commented blond Janis Ryan, who was dashing between her office at the Bank of American building and McDonald's for her lunchtime fishburger. "He's kind of cute. It's a nice idea."

A more cynical Duane Self, a buyer for a general contractor, said "It's a gimmick. I can't say opening and closing a door will improve business."

A few women said they found the doorman to be an anachronism who made them laugh but did not endear McDonald's to them. But most who were interviewed said they enjoyed the presence of the top-hatted gentleman, although one pedestrian, Michael Houston, said neither a doorman nor anyone else could persuade him to eat at McDonald's because "I'm a vegetarian."

Diaz says that when he took over the financial district shop, he found customers were "nasty," and "negative."

The particularly difficult clientele "want to come in and out and they don't give you too many chances."

To cope with it Diaz said, "I went back to the basics and hit people with good service."

"Now we have good rapport" with the customers, he says. And he won't stop using doorman Miller.

Diaz is talking about tablecloths for the upstairs tables. Although the place bears small resemblance to the typically plastic motif of other McDonald's, there remain a few touches of fast-food style. In one leather-like booth, is scribbled the message: "Kitty n Bunny."

Recently, while visiting one of the posh restaurants here, Diaz acquired his next plan for McDonald's. Observing a bathroom attendant at work, he came away with the conviction that a curteous bathroom attendant was just what was missing at the financial district's McDonald's.