Ok, got it faster than I thought.
This is a basic GSTNet example to get started.
WARNING: This example is for users who know what they do. so, if you can't program in C-Lite you can't use this.

you can find the files here:
http://www.bysamb.de/priv/gstnet_example.zip

It's a basic example for a player movement over the internet. It just sends the keys you press and also the position, if you pressed a new key. this is good for arcade-like games.

open "snowball.wmp" and run it to test it.
"schneeballmain.c" is the main script file. I tried to comment everything, but, I think, everyone who had problems with GSTNet just want to see the main function.

Ok, I hope this will solve some of you guys problems
Now go out there and produce some multiplayer games!!!