I have a 2008 imac which has built in wireless. Is there some way to use the wireless to connect to internet while using the ethernet jack to connect to a different LAN so it can connect to a fileserver? Or if that isn't possible, can I join my LAN network to the one which provides internet access without having to change all my LAN addresses? My goal is to maintain a private gigabit LAN while getting internet from somebody else in my office. Thanks for your help. And please excuse my ignorance because I know very little about networking.