Can ICS be configured to use a different IP?

I am trying to configure ICS on a PC with a "mobile" broadband connection.
The internet conenction is on a user PC (XP) but the primary server for the
office was addressed using 192.168.0.1.

The goal is for one or two other PCs on the LAN to be able to access a
single URL/IP (with no DNS on the LAN, I can handle the single URL
restriction using HOSTS or a ROUTE entry on the individual workstations.)

The server IP is statically addressed in several locations on each PC in the
application configuration, so changing that is an absolute last resort. The
original server installation/application vendor would probably have to be
called in on Time-and-Materials, which would probably be a deal killer for
this particular application. This is a "customer" site where we are trying
to migrate them from a paper transaction to an on-line model, so I don't
have the authority to simply make that type of change myself.

Is there a way to enable ICS using a different IP on the "gateway" PC? Or,
can I take the PC where I want to configure ICS off the LAN to avoid the IP
conflict and then readdress it without disabling ICS?

C. Newell
Shiawassee County (MI)