Try to find Big-Tex tool setter screen set.
There is the exact functionality that you are looking for.
Initial setup: Use your ruby tipped probe for initial setup, machine will first touch off your stock, then it will travel to fixed probe location and touch off the plate.
Change the probe with your first tool.
Zero tool setup: machine will touch off fixed plate and you are good to go
For all subsequent tools, only use
Zero tool setup button.
As you will be using touch probe, set plate offset to zero (0)
Scripts that are behind these buttons work in metric and imperial units.
FYI Fixed probe location coords are in MACHINE COORDINATES so your machine should be properly homed.