I am going to try to answer you with my bad English .
I realized a workshop in 3 parts for the mode multiplayer. Both first parts are ended for the month by aout and are at Conitec for check and translation.
The first part is technical and resumes all the possible connections (nullmodem, modem, ipx and tcp).
The second part consists of the creation of a game of trick tap toe (game in the tour for 2 players).
The third part, a little more difficult to implement, will be a shooter for 4 players. I advanced well and it should be ended quickly.
All this to say that I a little studied the mode multi-player and that I can bring you some answers.
There are not other solutions that to launch the mode multi-player with -sv and/or -cl in the line of command.
I admit that it has a small puzzling side but one makes there very fast.
But this has nothing of exceptional. If you look at the example Maze 3d supplies with the SDK directx8 of Microsoft, there is a program to launch on the machine server and another program to launch on the machine client.
You can on the other hand manage in the starting up, a picture of wait of connection of the players with possibility of choosing its colour, accepting or refusing a player, and starting the game when you have your number of players