Script to award all the players the stat for Waffe in coop
Place this GSC in
%localappdata%\Plutonium\storage\t5\raw\scripts\sp
Next to zm_spawn_fix.gsc.
Load up Call of the Dead with your teammate(s), use sp_minplayers to ensure everyone is there from the beginning.
Once round 1 begins, the Waffe stat is awarded, and the game will end.
Remove waffe_award.gsc file, and you can play out your game.
Go here, press download in the top right part of the page.