the router can be configured by going to the IP address that should be listed in the manual. i have a netgear and it starts something like 192.168.X.X (i can't remember) it's the same addresse you used to control access, admin password and network name. (consequently, it's a VERY good idea to change the admin password... since this IP address assigned to the router is the same for all the models of a company, it's conceivable any wardrivers to just come by and configure your router with the default login name and password...)
one of the properties you can change is port forwarding. point that to whatever subnet address your computer is assigned to. now, under os X, turn on remote login.
if your router has a static IP, you can now ssh to that address from anywhere and it will get forwarded to your computer.
if your router has a dynamic IP, you will need to sign up for a service that will give you a static address to dynamic IPs. after you do that, i think you can ssh to that address... (this last part, i'm not very sure about at all. i'm very much an amateur about this...)
if anyone more knowledgeable knows how to do this, please follow up.