Let's assume your network is 192.168.0.0/24. For historical reasons, your servers are between 192.168.0.50 and 192.168.0.60. You want to move the workstations to NewGroup and keep the servers in their old group. You can write an IPGroups.txt file like this:
192.168.0.1-192.168.0.49,NewGroup
192.168.0.61-192.168.0.254,NewGroup
Another possibility: If all your clients are Windows XP boxes, edit the OSGroups.txt file this way:
Windows XP*,NewGroup
IPGroups.txt, OSGroups.txt and some other files are controlling MoveClient.vbs. Have a look at MoveClient.pdf in the MoveClient folder on the CD.