If I remember correctly from when I set mine up, you should be able to define an IP address under the 'change node-name' command. I am, of course, assuming you have the C-LAN card to install. After you've set the node-name you define the C-LAN location and node to use under 'change ip-interface'.
I notice you say change the IP address, as I'm sure you know, if you have one defined that's interfacing with another system you don't want to change it withough telling the other system. Another problem I've encountered is I haven't been able to telnet my switch using it's IP, it'll ping all day long and interfaces across the LAN to adjuncts but I can't get to it from my PC either using DSA or just straight up telnet. If there's a way and I'm missing it I'd appreciate a heads up.