thanks andypugh, but i can't figure out what goes in the [ ].
i understand #2 = [#2 - #3] equaling -.01, so it would move down .01 each pass(or run of code)?
but no idea what [#2 GT #1].
i'm guessing GT is GoTo. what does the While ? xy or z?
<G-Code goes here> where is the "While" telling Z to do anything ?

that D### z. thanks for your help !
andypugh wrote:Yes, that is pretty much what the functions are for
#1 = .778
#2 = 0
#3 = 0.01
O100 DO
#2 = [#2 - #3]
G1 Z#2
<G-Code goes here>
O100 WHILE [#2 GT #1]
<finishing pass at Z = #1>