The search for the perfect star shack begins with a few bars of "My Sharona."

In the market for a Hollywood home? If you’re Claire Danes or Leonardo DiCaprio, the search for the ideal domicile begins with the answer to the trivia question ”Who’s the girl in the Knack‘s 1979 hit single?” — Real estate agent Sharona Alperin, 37, is, indeed, that Sharona. Working out of the Sunset Boulevard office of the Dalton, Brown, and Long firm, Alperin, just 17 when she inspired the lecherous No. 1 new-wave ditty, has avoided obscurity by becoming a top brokerata.

In the last three years, she’s found a cozy nest for new mom Julianne Moore and bachelor pads for New Line’s bad-boy president of production, Michael De Luca, and the Red Hot Chili Peppers’ Dave Navarro. (”Bachelors want a sexy view house where they can score,” she says.) She unearthed L.A. outposts for New Yorkers like Danes, who needed a place while doing The Mod Squad, and producer Darren Star (Sex and the City). And she may deliver DiCaprio from his nomadic post-Titanic existence by finding him the perfect L.A. hangout.

”I sell the most emotional product on the market, because a star’s home is their only safe haven,” explains Alperin, wearing knee-high Calvin Klein boots and a tartan skirt and looking very much the rocker’s muse. ”Most of my first-timers are buying houses for between $750,000 and $1.5 million. That’s pretty amazing for people moving from apartments.”

Clearly, one of the catalysts for Alperin’s success — she made a record 47 transactions in 1997 — is her own deer-in-the-headlights stardom. She was just an adventurous Fairfax High School senior in 1978 when the Knack’s lead singer, Doug Fieger, met her in the clothing store where she worked. He persuaded her to dump her boyfriend and tour with his band. A hit song, the cover of the second album, …But the Little Girls Understand, and a failed engagement to Fieger (and two more to other beaux) followed before Alperin got her real estate license. ”My life was decadent then,” she admits. ”When Doug was looking for houses, he was always on tour, so I would house-shop in the limo. I’d choose five houses and then show him. One of the agents said to me, ‘I’ve never seen anyone show houses like you; you should be an agent.”’

Alperin, who calls her clients ”sweetie,” has been putting showbiz types in their dream houses for 11 years. She works seven-day weeks, logs roughly 225 calls each weekday, and can name-drop with the best of them. While confidentiality agreements are standard, she goes further: Her client list is written in code. And the encoding is done in her surprisingly unplush cubicle with a Sunset Boulevard view. She drives a four-door BMW, rather than a Range Rover: ”My clients don’t go house shopping to get a workout climbing in and out of their broker’s car.”

Sharona’s specialty? Houses that aren’t for sale. Shopping for writer Daniel Waters (Batman Returns), she nabbed the house where Orson Welles lived. Waters now welcomes visitors by showing them the spot in the dining room where the director keeled over. ”It’s a great conversation starter,” he says.