Oh I see. So you mean I could simply assign like "shift" or "alt" to one key on the G13 (or WoW mouse) and then press that key together with the normal button on the G13 to make it go to WoW as Shift+Key?
Well, sure, good idea. Gonna give it a try

Yes, I do have like "Shift Ctrl F1" for example assigned to one key on my G13 or G15 in this case. Pushing modifiers didnt work because I was not using my hands on the "normal" keyboard ... I just wasnt thinking about to assign shift or alt on my G13 to use it.