Pretty cool Todd, I assume you just wrote that off the top of your head and didn't get a chance to debug it. I took the liberty to debug and repost a working example. I need to add that to the docs. BTW, if you use %'s you don't need M2, if you use M2 you don't need the %'s because anything after M2 is ignored.
Code:
(Use _count as your part count variable and create it if it doesn't already exist)
o10 if [EXISTS[#<_count>]]
(debug, _count exists and is #<_count>)
o10 else
(debug, _count does not exist setting to 0)
#<_count>=0
o10 endif
(insert the g-code to make your part here)
#<_count>=[#<_count>+1]
(debug, Part count is now #<_count>)
M2
JT
