Thanks for all of the info. I had the command:

G1 X170 Y0 (X axis inverted on this printer)

that I wanted to insert, but for the life of me I couldn't find the place to put it (obvious once I was led to it).

Also good to know about the G91 command - I didn't want to "home" the Z Axis for the reason stated above, but now knowing about G91 I can safely raise the head regardless of where the print left off.