Ras / Dialup

My company is renting space from another company. We share the Hubs, Switches, Firewall, Routers. We have one Windows 2000 Server Box connected to the equipment. So they provided us with private addresses.
Now I would like to work from home, But They won’t open a port for me ( I don’t blame them). I would like to get an extra telephone line in my office and connect it to a modem on one of my workstations, so I could have access to my server from home. I have an Idea of how to go about it, but i’m not to confident. Other users like the BOSS would like to do it too. How would I go about setting this up. Is it a difficult process? The workstations are Windows 98/Me.
Thanks
Mervin