Currently Being ModeratedMay 9, 2012 5:42 AM (in response to Rick Jiang)
Not what you're asking and obviously a guess as to why you're doing this (and why you need this isn't stated)...
Switch all three WiFi devices over to access point (what Apple calls "bridging") configurations and eliminate this particular complexity from your network?
Not the answer to the direct question, but this'll work for one of the more common reasons folks ask this, and it'll make end-user operations in your network easier. One password across all. And this also allows roaming across access points without having to reset the connections, for instance.
Currently Being ModeratedMay 11, 2012 2:49 PM (in response to Rick Jiang)
why not set up three different locations, one for each WiFi connection? (System Preferences -> Network Preferences -> unlock and choose Edit Locations from the locations pull down.) If I remember right, it's easy to script a location change.