‘Beauty’ doesn’t do Duff any favors

That is not meant as faint praise. Negotiating fame’s tricky curves is a skill all its own. To her credit, in the decade since she became a tween fave with the Disney Channel’s “Lizzie McGuire,’’ Duff has managed to keep her career on track, while her onetime counterpart in teen stardom . . . hasn’t.

When it comes to acting chops, however, there is just no comparison. Take “Beauty & the Briefcase,’’ which airs on ABC Family tomorrow at 8 p.m. Lohan’s native wit might possibly have turned “Beauty’’ into an enjoyable wad of bubblegum. But Duff’s default impulse is invariably to preen or mug rather than act, and that, along with a leaden script, helps to sink this highly derivative movie.

Duff plays Lane Daniels, an aspiring fashion writer whose ambition to break into the big-time magazine world is matched only by her desire to find Mr. Right. She finds a way to combine the two pursuits when the editor of Cosmopolitan magazine (played by Jaime Pressly) assigns her to go undercover in the corporate world to write a story about finding romance in the workplace.

“You have to get a real business job, and you have to date men in suits,’’ the editor sternly instructs Lane. So she bluffs her way into a job at an investment bank and begins dating men in suits. Lane is willing to pay any price to get published in Cosmo, which she calls “the greatest magazine of all time.’’ (Take that, New Yorker!).

Though she becomes smitten with a fellow she meets outside the office — the dashing Liam, who claims to be a British record producer and who fulfills most of the items on her perfect-man checklist — Lane eventually goes out with pretty much every guy at the firm, except for Tom, her uptight boss. Tom, you see, utterly flunks the checklist test.

If you don’t know how this plays out, you must never have seen a romantic comedy in your life.

As it trudges down its formulaic path, “Beauty’’ takes time to shamelessly pillage “The Devil Wears Prada’’ (and no, having Lane exclaim “I’m like Anne Hathaway in ‘The Devil Wears Prada’!’’ doesn’t get the creators off the hook), “Legally Blonde,’’ “Working Girl,’’ “Sex and the City,’’ and “Sex and the Single Girl.’’

Speaking of sex: The characters in “Beauty & the Briefcase’’ do a lot of speaking of sex. It’s a little creepy for a movie on something called the ABC Family channel. Parents beware: Despite its name, ABC Family’s target demographic with movies like “Beauty’’ is clearly those advertiser-coveted viewers 18 to 34. Yet it’s hard to imagine viewers of any age thrilling to lines of dialogue like “I just want to find my magic man!’’ and “Well, you know what they say. Humor plus business makes for funny business.’’

There’s nothing funny about the way the movie wastes Pressly, who’s so wonderfully deranged as Joy in “My Name Is Earl.’’ The Cosmo editor is less a role than a straitjacket, and Pressly does not escape, even though she tries to liven things up by wearing red lipstick she apparently borrowed from Dame Edna and a hairdo that seems to be welded onto her head.

And Duff? Well, she clearly is using “Beauty & the Briefcase’’ (and some racy guest appearances on “Gossip Girl’’ last year) to transition into adult roles, and there’s nothing wrong that. But the problem is that in leaving behind the girl-next-door quality that made her so appealing on “Lizzie McGuire,’’ she has replaced it with the generic glam poses of a thousand other actresses. While Duff occasionally shows an aptitude for screwball comedy, most of this movie seems to be about nothing more than how great she looks in one skin-tight dress after another.

Title this one: Beauty and the Bad Career Move.

Don Aucoin can be reached at aucoin@globe.com.