Remote Access Query

I have a small network 4pc’s\laptop’s and a Server.
Pc’s and Server have static IP Addresses and access the internet thru a Internet Access Server (IAS), the IAS is connteced to a small hub/switch and has DHCP disabled so as pc’s can use ‘autodetect settings’ to access the internet

The server has an internal modem contected to a line that shares a fax.

Now my Q’s are: should I dial straight to the modem on the server or can I do it thru the IAS?

If I use the modem will I have to enable DHCP on the IAS or Server ’cause it prompts me in the wizard to configure it, ….I didnt want to mess with IAS cause i didnt want to screw with something that works.

Basically I want Remote Access, …can someone help?