Connecting Router to a network as a wireless modem

I have a small wireless network, comprising a couple of Macbook Pro’s, wireless printer, couple of Iphones, and new time capsule. What I wanted to know is whether I could hook my existing Linksys router (g) up to supply wireless internet access to my time capsule basestation instead of plugging my modem into the WAN port on the basestation directly?
If possible, any advice on how to do this would be appreciated.
TIA
Paul