OpenLevel with listen and port=number

Up that post. I tried a lot things and it never works. The only way I found is to change the source code engine to allow this feature.
Anybody ever meet this situation ?
thanks.

Hi there,

I’m working on a multiplayer-side of a game. I want to use OpenLevel with option listen and specify the port to use.
With the command line, we can use port=myPort but from c++ function OpenLevel it does not work. The host start well but listen on a random port :s.
We use our own network engine to find which port the host must listen because we are in peer to peer configuration, so we really need to specify this port at runtime.

I hope someone has the solution to our problem. Thank in advance to any contribution.
Vincs.