Problem with remote connect using ATT DSL

I’m trying to use remote connect at home to connect to my server at work. At the host we have a Linksys WRT54GS router with a ATT ADSL internet connection. My question is this, can I connect to this using only an IP address with specified port, or does ATT DSL require that I set up a “Dynamic IP” address? I’ve tried using only the IP address assigned to the router with the correct port of 3389, but with no sucess. Does anyone have any experience setting this up using ATT ADSL?
Thanks