Creating a different wireless LAN for a device

I need to run one network device (similar to that colour changing orb) on a wifi network. The problem is that this device will only operate on a WEP encrypted network and our existing network is WPA and uses radius authentication. One of our G4 Servers has a existing apple airport 802.11b card inside. Seeing as though this device only needs to access one port at a certain server, I was wondering if I could somehow create a virtual wireless WEP encrypted network inside out existing network using this card and limit access to this server xyz.com:9999. This level of control would be a ideal solution as there would be very minimal epxloitable options with this wifi connection as it would be a visible wep encrypted network.

My question is, how can this be done in tiger sever (on a machine that is already hosting LAN AFP/SMB and DNS services).