"Cafe Express," an Italian movie now at the K-B Janus 2, evidently grew out of director Nanni Loy's encounter with one of the most unfortunate characters he's ever met on the train between Naples and Salerno. uNino Manfredi stars as the fictionalized version of this real-life model, an unlicensed coffee vendor who sustains a precarious living by peddling diminutive cups of coffee to the passengers on a night train.

This illicit profession obliges the vendor, called Michele, to play a constant game of cat-and-mouse with railway employes. He apparently has eluded them for years, but his luck runs out on the trip depicted in the film. Following a night of artful dodging, the morning finds his in the custody of an imperturbable railroad detective played by Adolfo Celi. Nevertheless, it appears that bureaucratic inertia and indecision will probably leave the incorrigible, self-righteous Michele free to ply his disreputable trade the next time the train pulls out.

Loy misplays his hand by insisting that Michele's hustle has stubbornly heroic and even inspiring dimensions. There are underdogs and underdogs, but Michele may be too far submerged in eccentric squalor to inspire anything but weary distaste and a conviction to avoid the Naples-Salerno run. The characterization seems to be trapped somewhere between Manfredi's portrayal of the lovable persevering exile in "Bread and Chocolate" and his portrayal of the corrupt old shantytown patriarch in "Down and Dirty."

Although Loy seems predisposed to sentimentalized Michele, Manfredi's performance leaves an ambivalent impression. Michele has stock rationalizations for his desperation -- physical disability, a little boy in need of an operation -- but Manfredi doesn't embody the sort of underdog you'd feel comfortable sheltering. He has abrasive, obsessive quirks that suggest a permanently damaged personality. You suspect that this underdog has become so used to mean circumstances that he needs them for self-justification.

As a result, the movie's attempts to celebrate Michele as an endearing rogue are more dubious than amusing. His degraded status also inclines the humor in a slightly excruciating direction. For example, the biggest yuks are supposed to be provoked when a vindictive hood spikes Michele's thermos bottles with urine. You don't exactly await the payoff with eager anticipation, and Loy seems far less proficient at obscene facetiousness than Cheech & Chong, who finessed the same situation in their second movie. Still, the wonder of it all is that Michele persuades anyone to buy one of those outrageously teeny cups of coffee. Aren't there any serious coffee drinkers in that country?