toggle axis 4 dro to a-b-c

Gooday
Im trying to run reprap gcode to extrude parts.
The two steps in this are using E for extrude and F which is a temperature setting.

I have been able to assign the E for extrude axis in the G code to C axis using search and replace text editing.

I want to be able to toggle the 4 dro in program1 and mdi screens between A, B, C, axises.

While I can see all six axises in the diagnostics screen.
Thanks Peter.

I'm pretty sure you can't toggle the DRO display, but you can use the Swap axis command, which will basically use a different axis then the programmed one.

Thanks, that would work if I only needed to see four axises.
I plan to use five or six axises, and would like to toggle the fourth axis dro to check important movement as required.