Ya i know about the hidden menus. Just don't know if they actually work if used or not. I haven't had a chance to try them out yet. If the menus do work then I presume bridging and possibly using the WDS option should be able to connect to and bridge to the 855.
Theoretically, using the WDS should work to help extend the WiFi.
BTW, what HW version is the 4500? Curious.