Ok, I managed to log into my router to make port forwarding changes (typed in the IP in the address bar, logged in with the wifi access username and password).

I have:
-Single Port Forwarding
-Port Range Forwarding
-Port Range Triggering
-DMZ

I have setup what I believe to be configurations to forward connection attempts via the router IP to port 3389, however rdesktop is still unable to connect. I have disabled firewalls on the desktop I intend to access (desktop connected to wirelessly to router), as well as enabling access via Remo9te Desktop (through Windows Network Manager). The desktop doesn't have a Windows log in, you just push enter on the username without a password and it goes through.

Not sure what more I can do!