Molly Ringwald appeared in John Hughes' first two high school movies, "Sixteen Candles" and "The Breakfast Club" -- so it makes sense that the actress would be on hand for round three, "Pretty in Pink." But the announcement that Harry Dean Stanton will play Ringwald's father raised a few eyebrows. Stanton's a terrific actor, mind you -- lots of folks still think it's criminal he didn't get an Oscar nomination for "Paris, Texas" -- but he looks significantly seedier than the kind of father Ringwald usually has in Hughes' movies.

In this film, it seems, her character doesn't have a comfortable suburban upbringing. "She's a poor girl from the wrong side of the tracks going to a predominantly rich high school," says Ringwald. "Her mother left the family when she was a baby, and her father's sort of a degenerate, you know?" That explains Stanton -- though Ringwald hastens to add, "It's a neat script. Sweet, kind of like an old-fashioned love story" . . .

Paramount's "The Untouchables," a film version of the violent early '60s TV series, won't be a satire or a spoof, although that had been considered while the studio was securing the rights. Producer Art Linson has guaranteed a serious look at crime-fighter Eliot Ness by hiring Pulitzer Prize-winning playwright David Mamet to write the screenplay. Mamet, author of "Glengarry Glen Ross" and the screenplays to "The Postman Always Rings Twice" and "The Verdict," attended a Chicago high school directly across the street from the garage where Al Capone conducted the infamous St. Valentine's Day Massacre. (Ness, the Prohibition-era fed who arrested Capone, was the central figure in "The Untouchables.") No cast or director will be hired until Mamet finishes the script, says Linson, who has a far better track record as a producer ("Melvin and Howard," "Fast Times at Ridgemont High") than a director ("The Wild Life," "Where the Buffalo Roam") . . .

"Cocoon" edged "Rambo" to become the country's biggest moneymaker last weekend, an achievement made more impressive when you consider the Ron Howard film played in about half as many theaters. But "Rambo," which just passed the $100 million mark, stayed ahead of "Goonies" and soundly beat new entries "Return to Oz" and "Lifeforce." "Return to Oz" got off to a dismal $2.8 million start, while "Poltergeist" director Tobe Hooper's "Lifeforce" earned a slightly better $4.2 million in spite of mostly negative reviews -- and in spite of being the movie that, according to more than one Hollywood cynic, "proves that Steven Spielberg really did direct 'Poltergeist' " . . .

Director Milos Forman will make his acting debut in "Heartburn," the Mike Nichols film of Nora Ephron's book. Meryl Streep, Mandy Patinkin and Maureen Stapleton star . . . Rosanna Arquette has replaced Jamie Lee Curtis as the female lead in "8 Million Ways to Die," a $16 million police drama about a prostitute who may help solve another prostitute's murder. Jeff Bridges also stars in the film, to be directed by Hal Ashby, whose last film was the late, unlamented "The Slugger's Wife" . . .

Director Albert Magnoli helped turn a rock 'n' roll singer into a movie star when he made "Purple Rain" for Prince -- now he'll try to do the same for an Olympic gymnast. Mitch Gaylord will play the male lead in Magnoli's "American Anthem," which starts shooting in September for Lorimar. Let's hope Gaylord fares better than Kurt Thomas did in "Gymkata" . . . And Tina Turner, who makes her major movie debut alongside Mel Gibson in next month's "Max Mad Beyond Thunderdome," is reportedly considering a script by John Milius, who rewrote "Dirty Harry" and has apparently written a script about a Dirty Harriet-style character. Turner's manager says she's already turned down a lot of "black hooker" parts, a role in a film based on the title track to her "Private Dancer" LP, and a role in "The Color Purple," which she considered too weighty for this stage of her acting career . . .

The Coca-Cola Co., which owns all of Columbia Pictures and a third of Tri-Star, recently bought Embassy Communications. Embassy's biggest 1985 release is its $30 million version of "A Chorus Line," due out at Christmas. "A Chorus Line" has already made a deal for a commercial tie-in with Pepsi-Cola. Stay tuned . . .