"Tactical retreat"( I think thats the name of it) allows the LS player to return a card he controls to its owners hand. Does this allow him to rescue a captured card?

It doesn't, since captured cards aren't in play. Cards only affect in-play cards unless specifically stated otherwise.

Ahh. Thanks very much for clearing this up!

If you are thinking about Leia, use it on the front side and then take the objective on which they capture.