Mirroring a multiple part layout

[ParadoxComplex]

Hello. I'm new here. I couldn't get the answer to this question from my boss so I'll assume I'm now pass his knowledge in g-code programming, and seek outside support here. I need to mirror the following program. I'm running a coma turret with Fanuc controls, and a PC Controls PC800 (aka crap interface.)

I don't remember the exact dimensions of the blank so lets just assume that it scales. I need it to mirror on the y axis. The current program is as follows. I flip the part to achieve the mirror.
G92 X72.Y60.
G90

G98I5.P4.

U1
X.5Y1.5 T*** (***)
G36I4.J2.P1.K1.
V1

U2
X2.Y1.75 T***(***)
V2

U3
NEW TOOL
V3

U4
NEW TOOL
V4

U5
NEW TOOL
V5

U6
NEW TOOL
V6

G75Q1W1
G75Q1W2
G75Q1W3
G75Q1W4
G75Q1W5
G75Q1W6
G50
%

I tried a g73 for each block but it only mirrored the first part. I think i need to nest the macros but I'm not sure how that works. Thanks in advance. Anything you give me is more helpful than what I get from my employer.

Also on a side not if anyone could recommend a good cheat sheet for g/m-code regarding hypertherm plasma attached to the same setup that would be great. I grasp the g-code fairly well but know nothing about the plasma end. I'm looking to learn.