KEATON SUPERB IN `MULTIPLICITY'.

Byline: Bob Strauss Daily News Film Critic

``Multiplicity'' makes you wonder who the fifth Best Actor Oscar nominee is going to be.

OK, the other four slots probably won't all go to Michael Keaton. But his astounding performance as this emotional comedy's harried householder and his three clones is so technically adroit - not to mention hilarious, moving and, in the most honest sense, self-centered - it deserves at least some kind of special award. Maybe four.

``Multiplicity'' is another clever contraption from director Harold Ramis, who also gave us the marvelous time loop fantasy ``Groundhog Day.'' Like that film, ``Multiplicity'' sucks a troubled man into a weird gimmick, which causes him no end of frustration but, finally, turns him into a better person.

Keaton's Doug Kinney, however, is not half the creep Bill Murray started out as in the earlier picture. He's just so overextended, and so self-pitying about it, that he can't do justice to his ever more demanding job, his wife and two kids or long-suppressed personal needs.

A supervisor for a thriving but understaffed Los Angeles construction company, Doug has to deal with inept subcontractors on job sites and workaholic careerists at the office. His wife, Laura (Andie MacDowell), has stayed at home with their two raucous children long enough and would like to return to her old real estate sales job - if only Doug could dependably share the parenting load. Meanwhile, half their rambling house is decorated in plastic sheeting and exposed lumber, a monument to the home improvements Doug never has the time to finish.

All of this, quite understandably, leads to angry outbursts. When Dr. Leeds (Harris Yulin), the head of a Malibu research center, observes Doug's stress, he offers the perfect solution: a clone with all of Doug's memories, who can share the workload and provide the original with more personal time.

Doug installs Two in the apartment above the garage, and things indeed get better for a little while. But there are two glitches in the scientific program: Two's pronounced testosterone level makes him a great worker but also aggressive and difficult, and Doug doesn't share any of Two's post-cloning knowledge.

There's also a major human imperfection that comes into play. Doug still feels he doesn't have enough time to do everything he wants, so he gets another clone. Three is sensitive and nurturing and a lot more patient with the kids. But then Two and Three get antsy and clone Four off of Two; being a copy of a copy, he doesn't come out so clearly, and seems arrested at the developmental stage of a slow 6-year-old.

Naturally, Doug's exponentially problematic little secret causes escalating confusion, both on the job and, especially, for Laura, who can't understand her husband's wildly shifting moods and failure to remember recent conversations. Yes, all the clones end up in bed with her (the movie's comic high point, which also makes you wish for a little less sentimentality and an extra wacky set piece or two), which leads Doug to seriously question the marvels of technology.

Even though it's the technical genius of Richard Edlund's special effects crew that makes ``Multiplicity'' possible, it is Keaton's heartfelt characterizations that make it matter. He carefully calibrates each Doug's personality and development, then mixes them up with the other selves without ever losing track of who's who. As astonishing as it is to see three Keatons shaving - in the same shot with two sets of mirror reflections! - or Doug pouring Coke into a glass held by Four, the most impressive miracle here is how Keaton highlights the many sides of modern man.

Bravo to MacDowell, too, who brings her own convincing shades of multiple personality traits to the most demanding of straight roles.

Any man who's ever felt guilty about not doing all he should, or felt cheated out of doing so much he'd like to, will make a soul connection to Doug. Often while laughing their heads off, like many others who'll be watching ``Multiplicity.''

THE FACTS The film: ``Multiplicity'' (PG-13; sex, language).

The stars: Michael Keaton, Andie MacDowell, Michael Keaton, Michael Keaton, Michael Keaton.

Behind the scenes: Directed by Harold Ramis. Written by Ramis, Chris Miller, Mary Hale, Lowell Ganz and Babaloo Mandel. Produced by Ramis and Trevor Albert. Released by Columbia Pictures.

Running time: One hour, 50 minutes.

Playing: Citywide.

Our rating: Three Stars.