Man, I feel really stupid for not thinking of such a simple solution!
Anyway, I made three copies of the addin with different names, menu items and accelerators and toy with it a bit. It still seems to be failing.
Since the concept is perfect there must be a bug somewhere, but I couldn't find it yet. It would be good to polish this up a bit so we can include this routines in the addin template.
EDIT: attachment removed. saving some space...