I woke up in the middle of the night last night in a cold sweat, realizing that I'd gotten it backwards. I was worried that at the very least I'd confused you, and at most you'd post back saying "uh that don't work!" Either way I knew the cold hand of fate would lead me once again to this thread, and with a foreboding sense of dread I settled back into uneasy dreams.
Um... anyway. Using a loop you can disable all of the numbered groups, like so:
->Set global('groupNum') to whatever group you need
->Set global('loopNum') to 1
+For 1 to 9
->System: Disable group "Group"&global('loopNum')
->Add 1 to global('loopNum')
->System: Enable group "Group"&global('groupNum')
The loop cycles through all the groups and shuts them down one at a time, then the following event activates the one group you need. And instead of a loopNum variable you might be able to use the loopIndex expression, but I don't recall off the top of my head if that works with For loops.