You may need to copy a steam_api.dll from any other game and that should work. Steam networking/matchmaking will not be available and you will have to port-forward or use Hamachi/etc.
I have tried port forwarding and my friend got Connection_Timout Every time. I created a static IP for my computer port forwarded to the default 5394 port, and when he types in my static IP and port 5394 it does connection timeout. Could you write a short tutorial of which IP i should use to port forward to or how to get this to work>