Networking with Parallels on iMacs

We just purchased our second iMac -Mac OS X (10.4.10) - for our office. They are identicle Macs but our current Mac runs on Tiger and the new one on Leopard. The two have been networked and recognize each other but I can't seem to figure out how to network the two within Parallels. We have an office program that is only Windows compatible and we need it to be shared between both on the network and able to keep them updated and usable on both systems. Can anyone help?
Thanks!

 

Please clarify one thing for me. Are you trying to have a Windows VM on an iMac running Tiger communicates with another Windows VM on a different iMac running Leopard?

What do you mean by "keep them updated and usable on both systems"? What are you trying to do exactly?