Not quite sure what you are asking but I will have a couple of guesses.
In Turn tools are called in the format T0131 where the first part, 01 is the tool number, the second part, 31 would be the offset number as in the tool table.
If you are wanting a DRO to show the offset number then afraid there is not one, hopefully this will be added to the next revision of Mach as it is something I have been asking for for a long time.
Hood