I’d like to give Nora Ephron credit for taking the high-concept comedy into the realm of the meta-high-concept comedy with Bewitched. That, however, would require the assumption that Ephron knows what she is doing as a filmmaker. And anyone who has directed Mixed Nuts and Lucky Numbers in one lifetime has earned no such benefit of the doubt.

Still, it’s pretty weird. Here she’s gone and crafted a re-imagining of the vintage mediocre 1960s sit-com that’s more entertainment-industry goof than faithful duplication. Will Ferrell plays Jack Wyatt, a fading movie star whose last crashing failure of a black-and-white artsy drama--“It’s the only movie ever not to sell a single DVD,” notes his agent (Jason Schwartzman)--has him grasping for a starring role on a TV show. The vehicle will be an updated version of that vintage mediocre 1960s sit-com Bewitched--and just to make sure no one steals his thunder as Darren, he wants to cast an unknown like Isabel Bigelow (Nicole Kidman) as Samantha.

Now here’s the ironic part: In the show-within-the-movie Bewitched, ostensible center of the project Jack discovers that the audience only really seems interested when Isabel’s on screen. And in the movie itself, Kidman’s character is the ostensible center of the project, but the audience only really seems interested when Ferrell’s on screen.

Isabel, we quickly discover, is an actual witch, longing to give up a life of instant gratification for mortal normalcy. She wants love, and that’s what Ephron wants to give her. Ephron also wants to give Kidman the same kind of spunky, pouty-cute character typical of the collaborations with Meg Ryan--When Harry Met Sally, Sleepless in Seattle, You’ve Got Mail--without which neither Ephron nor Ryan would have anything resembling a Hollywood career. Ephron’s not just making a movie about the making of a sit-com; she’s a writer with a sit-com sensibility creating sit-com dilemmas.

But Ephron’s also got Ferrell, who’s not about to sit still for something that conventional. Ferrell may already be the most ferociously brilliant comic actor working in movies today, capable of giving mundane lines a static charge. He’s hilarious both as a celebrity basking in his own egomania--“Make me 20 cappuccinos, and then bring me the best one”--and as a moony suitor when a hex has him falling for Isabel. The force of his presence drives nearly every laugh Bewitched has to offer (until his Anchorman co-star Steve Carell shows up for a merciless Paul Lynde send-up as Uncle Arthur).

It’s exasperating, then, watching Bewitched spend so much time trying to cram the witchcraft element of the story into a Will Ferrell showcase. Isabelle dutifully wriggles her nose, her warlock daddy (Michael Caine) shows up periodically in an ascot, Shirley MacLaine does what amounts to a cameo as the diva actress playing Endora, and Aunt Clara (Carole Shelley) drops down the chimney for reasons I still can’t quite fathom. Bewitched often doesn’t make a hell of a lot of sense, primarily because it often seems like Ephron is hamstrung into using touchstones from the original series that have nothing to do with what--or, more accurately, who--is actually funny about this movie.

Truth is, it’s not really clear what kind of movie Bewitched is trying to be. There are moments when Ephron looks like she’s aiming for her comfort zone of upscale romantic comedy, complete with simpatico gal-pals with whom Isabel can kvetch. Then she’ll veer off into slapstick. Then there’s a bit of show-biz satire complete with James Lipton and Conan O’Brien appearances. And then there are purely Ferrell bits of business that feel far too subversively original to have come from Ephron’s rim-shot-fueled word processor.

So we’re left with a strange kind of brand name cash-in, a movie that feels like every attempt to justify using the title Bewitched feels forced. Kidman is a fine actress, but there’s no reason to care about Isabel’s desire for the simple life (or enough made of the fact that she’s looking for it in Hollywood). If you’re like me, you’ll spend half of Bewitched laughing hysterically, and the other half wondering, “Can’t I just see a movie about Will Ferrell as a washed-up actor, please?”

BEWITCHED **1/2 Starring Nicole Kidman, Will Ferrell, Michael Caine. Rated PG-13.