Okay, here is the procedure that each player via Gameranger should follow:
1) Download the .bat to .exe file converter here:
http://www10.zippyshare.com/v/96862197/file.html
2) Rename your "graw2.exe" file to "graw22.exe "
3) Make a copy of your mod's batch file and rename it to "graw2.bat". Open the "graw2.bat" file and edit the command line to reflect "graw22.exe", save it, close the batch file. For example with Brettzies weapon mod 3.02 my "graw2.bat" batch file has the following:
"graw22.exe -o context_bp_weapons_pack_v3.02.xml"
4) Run the .bat to .exe converter and specify the "graw2.bat" batch file which you've just edited and then save the converted .exe file as "graw2.exe"
5) Run the new "graw2.exe" file you've just made.
6) Play!
Everytime you launch the new "graw2.exe" file you made, whether via Steam, or via Gameranger, it will always load the mod that you want to play. So, technically, GR will now think that the "graw2.exe" file you made is the new exe for the game, which will allow you to load the mod.
Also, I'm part of a project that is emulating Gamespy support, meaning that online play will be restored again via the game, without the need for Gameranger (or any of this batch file conversion). I'll keep you guys posted on further developments with regards to that. If you guys have any questions or comments about this method, feel free to ask