Create a bat file whith this for the server:

game.exe -sv
you can specify -port . ex(-port 2306)
there is a -tcp option , but i never tested it. i suppose it forces the server to run on a tcp protocol, by default its on UDP protocol.

and this for the client:

game.exe -cl -ip yourip ex(-ip 85.58.35.125)

if you are behind a router , you will have to foward the specifief port UDP to your computer local ip .

hope this helps.