thanks for this, I will take me a while to absorb all of this, but i
think i get the basic idea. Can you confirm my understanding of a few
points.
1) in the line "Private Sub mCBGroup_Change()" the word change could
be any of the applicable events for that class, initialize,
beforeupdate, afterupdate, etc?
2) and in the following line "MsgBox mCBGroup.Name & " has been
changed" ". That's where i would put whatever code or procedure i want
to happen with that event.

ok i think those are pretty obvious. now something a little harder.
the procedure that is called from each of the combobox_ change event is
called recalc(). It is slightly different with each userform, but the
same for each combobox within a userform. if the code in the class
module calls procedure recalc(), will it look in the userform code
window for the recalc() procedure, or will it be looking in the class
module, or will it be looking in the main module. I am not sure if i
am making this clear, but if you can figure out what i am talking
about, it would be great to get some more of your very useful advice.