You can't use that device as a wireless client. You'll need a dedicated workgroup bridge, something like the WET11 or WET54, or an AP with "client mode". There are a couple of AP/ROuter combo's now that have firmware that will allow them to bridge. I don't believe anything is available for yours though.
You would need them to both to be in wireless bridging mode. I don't believe either of those support that function though. Some people make tweaked firmware for linksys routers that give them more options, I'd look for that. Otherwise you are going to need a couple plain ol wireless accesspoints, they all have a bridge function. Or a couple wireless bridge devices.