Please Help! windows 2000 domain

Hi Experts, i am in a situation that i need to share a 56k dial-up connection to 5 users on a windows 2000 domain. Server is setup and running fine with the systems. All the systems can join the domain.

My problem is that the modem connection cannot be accessed from clients. It may sound silly that i am trying to share a 56k dial-up connection here. But at present conditions we do not have other option than dial-up to access internet.

Can anyone help me sort this out. I have done extensive search over forums/helps/guides and yet to find a solution.