Computer ? regarding modems and lans

I am running a small home network with three computers , one is an XP , and the other two are win2k.

Specifically the question is regarding sending faxes, all three machines have the software ,but as the puter tells me , the fax modem or printer as its called cannot be shared.
Its an external us robotics 56k , if anyone is curious.
UM before highspeed and such , some computer networks did hook up to a modem, with out one physically attached to the box, through a network.

Can anyone suggest how I might be able to share this modem , or am i out of luck

thanks

Declan

BTW , main internet connection is through a router with DSL

XP and 2000 Pro will not let you share a fax. I’m not sure if there are any good shareware or freeware fax packages that allow sharing. Commercial software like WinFax Pro will do it.