For a third-place network, CBS isn’t doing badly at all in the way of interesting summer programming. First the network gave us the offbeat Northern Exposure, and now the even more unusual Wish You Were Here. Cashing in cagily on the TV-video boom, Wish You Were Here is a comedy that offers, every week, a video letter from Donny Cogswell (young comedian Lew Schneider). Cogswell is a disillusioned stockbroker who chucks it all, buys a camcorder, and heads off to Europe. He bums around from country to country, making chatty tapes that he sends back to friends and family.

The setup for each episode is the same: Someone in America receives a tape from Donny (an ex-girlfriend, his grandfather), and then we watch the tape along with the recipient. As Donny, Schneider is a pretty funny wise guy; in attitude and looks, he’s a cross between Tom Hanks and Richard Lewis.

Narrating his wanderings through places like Budapest, Paris, and Barcelona, Schneider keeps up a line of hip patter. He’s only occasionally annoying, especially when he interrupts people in the middle of farming or sweeping the streets only to make fun of the fact that they don’t speak English.

Whenever Wish You Were Here isn’t busy being a commercial for Ugly Americanism, though, it can be clever. Donny’s guided tours of the towns he visits mix historical facts with autobiographical anecdotes in a breezy way. Then, too, the tapes Donny makes really are shot on 8-mm video, which gives them a pleasing roughness and immediacy — as does the way Schneider bounces the camera around, setting it on walls and tables to shoot himself gabbing. Quirky and unpredictable, Wish You Were Here is a charmer. B+