I got it figured out, with the following code in the screen editor:
GoToWorkZero()
local inst = mc.mcGetInstance()
mc.mcCntlMdiExecute(inst, "G00 G90 G53 Z0\nG00 X0 Y0\nG00 Z0")
I found a couple issues, the first being the "--" at the beginning, which ignores anything following! However, I had to add the "G90" as well, to switch to absolute mode.
Not sure if I need to put a "G91" at the end, to go back to Incremental, or is that automatic for jogging?