did you mean something like this:
G0 G99 U#5081 V#5084 W#5082 T0
G0 G97 X21.0 S2000 M3
G1 X-1.2 F0.015
Command M77 is for prevent the buffering (like STOPRE on SIEMENS) and disable the single block key on SR-20R. I hope this M code works on SR-20 too. In the 2nd line offset will be canceled without moving axis. 3th line checks if the y axis is greater then machine position -1 and the x axis is less or equal position 0 there are no need to cut off. N1 M78 is for enabling the single block key.
Hope it works for you. There are some initialization programs for star machines equipped with a fanuc control. Maybe i can help you.