Scott,
I almost always 0,0 in the center of my material. So consequently what i do to start out is do a C3 and go to table 0,0.

Then i manually move the bit to the center of the material (marked with an X) and then i take those coordinates that i move it to (say for example X 23.56 Y18.44) and i write them down on paper.

I then zero X,Y

so now if i lose position i just go back and do a C3, MX23.56, MY18.44 and i'm back to center of my material.
So your mod basically remembers that position for you and eliminates the need to do the manual repositioning correct?