Win2k Pro ICS and static ips

Is there a way to bypass the DHCP used with Win2k Pro and use static ip address? I have an NT 4 with Class A static network assignments. I want to be able to keep these assignments and also use ICS on this machine as a gateway. Can I change the default ip address assigned to the ICS machine by a registry hack like 98se and then assign all my machines gateway settings to point to the ICS machine for Internet access? Is this at all possible??

TIA,

John Stone