GOOD MORNING: “He is a genius — a true genius,” director Charles Shyer and wife/co-scripter Nancy Meyers chorused to me as we watched Steve Martin go through an intricate routine for “Father of the Bride 2″ on Stage 3 Thursday at CBS-Studio City. Martin, in heavy overcoat, polar fur hat with flapping earmuffs , was bounding between his very expectant wife (Diane Keaton) and equally pregnant daughter (Kimberly Williams). In the scene, both were panting on twin sofas during a record-breaking heat wave as Martin turned the air-conditioning even lower, alternately adjusting their pillows, pouring ice tea while tickling their feet, then rushing to get takeout dinners. For Martin (49), Keaton (47) and Williams (23), pregnancy is a new experience. But the Shyers are no strangers to impending parenthood — having welcomed two children — in the heat of the summer as well … In an earlier scene, Martin attends a slide aerobics class to get in shape as expectant father and grandfather. The producers brought up the gym scene on a monitor to further demonstrate Martin’s talents. Producer Meyers laughed so loud, the sound department threatened to put her in a closet, and cameraman Bill Fraker shook so hard from his guffaws, his crew took him off the dolly. Meyers said it was the funniest scene she’d ever seen. No argument from me … And when Martin Short and Steve Martin ad lib routines, the comedy’s compounded further. (Short returns for more segs of his NBC series when the pic winds.) They all agreed to this sequel — the original neared $ 100 million domestic — but cannot come up with a title, and a $ 1,000 reward’s been offered … Nancy Meyers will take on her first directing duties in “Love Crazy.” Keaton recently wound her Disney feature directing bow on “Unsung Heroes”… Martin, now onscreen in “Mixed Nuts,” will next star in Universal’s “Sgt. Bilko” for Imagine’s Brian Grazer and Ron Howard, for whom he starred in “HouseSitter” and “Parenthood.” Co-starring with him will be Dan Aykroyd as Col. Hall, Bilko’s bumbling superior, Phil Hartman as a general who has been trying to get even with Bilko for 20 years and Glenne Headley (who co-starred with Martin and Michael Caine in “Dirty Rotten Scoundrels”). There is no way the Army will cooperate with the making of this film, says Brian Grazer. “It is complete chaos — like ‘Animal House.’ “… On the serious side, Martin’s play “Picasso at the Lapin Agile” will probably run a year at the Westwood Playhouse, and there’s talk of N.Y. and London. Martin told me he has no plans for a TV or movie script — nor for him to take a role — well perhaps, a small one. He also has a “specialized,” 45-minute play, “Wasp,” en route to N.Y. boards. Does Martin have plans to direct? “Maybe later in life.”EDDIE MURPHY WANTS TO WORK more in ’95 and, after he winds “Vampire in Brooklyn” for Paramount and “The Nutty Professor” for Universal, he’s talking a non-stop action pic, “Sandblast” for Joel Silver at WB. Murphy, Silver and Mark Lipsky talked the feature over dinner at Morton’s for a September start … Ella Fitzgerald will be toasted Jan. 10 at U’s Amphi on her 60th anni in the biz. The night benefits Minority AIDS Project L.A.’s Dignity House. Performers expected include Tony Bennett, Smokey Robinson, Natalie Cole, Dionne Warwick, Nancy Wilson, Patti LaBelle, Mel Torme, Barry Manilow, Chaka Khan, Joe Williams and Liza Minnelli — her hip surgery permitting. It’s not yet known whether Ella will be able to attend in person. That day, Mayor Riordan will rededicate her star on the Walk of Fame … Doug McClure today gets his star on the boulevard. AFTER A TWO-DAY CONFAB in Montgomery, Ala., among “Grass Harp” producer Jerry Tokofsky, director Charles Matthau, New Line’s executive director of acquisitions, Amy Labowitz, and CAA’s Martin Baum (who reps Charlie), they all tell me peace now reigns on the set. Tokofsky calls Baum “Henry Kissinger” for his peaceful arbitration, and the producer claims Walter Matthau had a “bad hair day” when he reported grievances to me — and that Charlie was a “little emotional” as well. They are now on sked, I’m told — but still have to make up $ 250,000 over budget and all departments will have to work together to make it happen. Meanwhile, an arbitration is ongoing with the Directors Guild on behalf of two unit production managers who claim non-payment. Two others have settled, I’m told … Dawn (McElwaine) and Mitch Taubin welcomed their second daughter, Lacey Glenn, Dec. 8 at Tarzana Medical. Mom is VP, publicity & advertising, at WB; papa is partner in Telefilms Inc. Gramps is Guy McElwaine … Tony Goldwyn joins Mia Farrow, Scott Glenn and Mary-Louise Parker in Neil Jordan’s “Reckless” for Playhouse Intl. Pictures … Diana Ross, back from three SRO performances in Tokyo, is now looking to play her first North American tour in four years.