I have a D-LINK DIR-655 as my main router and I would like it to be set up like this:

DIR-655 ---(wireless)---> Airport Express ---(ethernet)---> Computer

I have already tried using the Airport utility to set it to join my existing network, but that resulted in "Unidentified network" on my computer (running Windows 7). Are there any specific settings that I need to change in my DIR-655? Any help is appreciated.