From point A to point B can be a journey of a thousand miles in a Claude Lelouch movie. In 'Cat and Mouse,' a kind of romantic mystery caper comedy now at the Fine Ars, Lelouch even has a rather devilish time simply getting to point A.

Lelouch, who burst onto the international filmmaking scene in 1966 with the deliriously dreamy "A Man and a Woman," a film of carcinogenic sweetness. This time he has chosen a quirky-jerky, loop-de-loop expositional sytle for what could have been a straightforward, engrossing tale of a seemingly murdered husband, apparently purloined paintings, and a faintly merry widow.

Perhaps Lelouch keeps changing the tone and direction of the picture for fear it will fall into one genre classification or another, or perhaps he just wanted to see how much he could complicate the elemental. Whatever the motive, he's made a movie primarily for those who never weary of double acrostics or who never tire of being tickled.

Others may find that it teeters perpertually on the brink of being fussy, busy and insufferable - as, perhaps, only a French movie can.

The abiding charm of the two lead actors, however, offsets a great deal of Lelouch's fey prankishness.As Inspector Lechat ("the cat," as high-school French would have it). Serge Reggiani is warmingly rumpled, worldly wise and roguish, bringing to mind. Norman Mailer in one of his pixilated, lap-dog moods. Reggiani is able to make Lechat endearing even when the inspector casually helps himself to a few thousand francs of stolen loot.

Michele Morgan is similarly engaging as the inspector's suspect and eventual romantic obsession, Madame Richard, whose husband (Jean-Pierre Aumont, briefly) dies early in the film, takings a number of very valuable paintings with him. Lechat is certain that the wife killed the husband for the insurance money and that the missing paintings are only a ruse.

When he attemtps to prove that Madame could have zoomed from a Paris movie house to the scene of the crime and back again within two hours - so as to have the movie as an alibi - the film takes off on an exhilarating jovride. Lelouch, who has always had a fondness for cars as movie vehicles, mounted a camera on the front of one and photographed a breathless drive - not really a chase - up the Champs. Elysees, around the Are de Triomphe, out into the countryside, and back again.

Then, knowing this sequence would be a rip-snorter, he has his heroes take the very same trip again, this time on a motorcycle. It's more fun than "Grand Prix," but it may make one wish all the more that the whole movie had been as direct about taking us where it wants to do.

Instead, the film diddles with perspectives from the beginning. Lelouch will jump suddenly to a fantasy sequence that seems part of the narrative, to half-completed flashbacks, or to a scene from the movie Madame Richard was watching, "The Lady, the Rolls and the Little Dog." Leiouch plays cat-and-mouse with the inspector and the widow.

Among other out-of-nowhere indulgences, Lelouch uses a subjective camera to afford us, for no discernible reason, the accasional points of view of the chief of police, a doctor or Sam. Lechat gallantly fails to train as a police dog. Lelouch wants us to know he has ooldes and ooldes of tricks up his sleeve. Some of them should have stayed there.

"Cat and Mouse," finally, has the effect of a light entertainment barging in one clodhoppers. It's cute, its perplexing and its clever, but it also becomes needlessly strenuous. The director seems so reluctant to bring the story to a conclusion that you almost wish he'd go back to "The Lady, the Rolls and the Little Dog" and at least finish that one.