as long as you have macro capabilities

#2001-#2064 are the wear offsets for fanuc
at the end of the program write a simple addition to the wear offset #2001=[#2001-.002] if you are changing parts and going deeper with a tool run program 20 times and reset the wear offset back to 0

by changing the tool wear offset for each part the math will need to be done before the tool offset is called. After the tool call it would not take effect until the next tool call IE run the part then the next part will be .002 smaller

#2001=[#2001-.002]
G43H1Z1.000


if you are looking to repeat machining with the tool dropping by .002 (same part/tool) a while/do might work

#100=0(Z start depth)
#101=.002(depth of cut)
#103=0(start of counter)
#104=20(number of passes)

WHILE[#103 LT #104]DO1
X/Y (POSITION)
G0Z#100
(MACHINE PART)
G0Z1.000(CLEARANCE IN THE Z AXIS)
#100=#100+#101
#103=[#103+1]
END1