Yes.
You can do it. You just need each computer to use different game ports. The default is 6112. The war2combat installer allows you to change to a different port number, or you can just change it in the windows registry.
under:
HKEY_CURRENT_USER\Software\Battle.net\Configuration
there is a key called "Game Data Port" (or if it isn't there, just create it).
It will be 000017e0 by default (6112 in HEX) Just change it to a different number >=1024 easy to just change the '0' on the end to another hex digit... 0->9 or a->f
If you both want to host you will have to set up 2 router rules mapping each port number to each computer's local ip address.
BTW the need to route ('open') all ports from 6112 to 6119 is a misnomer that has been around for many years, you only need to route your game port (6112 or whatever)