Rotary indexer - Lathe Tool Changer

Hi Group,
I'm in the process of making a Lathe Tool Changer and am wondering how
this would be controlled in Mach 3.
Would you use a normal encoder with 1 Index pulse per rev for a home
position as well as A,B channels ?
Has someone written a program to run in Mach 3 to control this ? It
could be just considered a rotary axis but would be easier to use if a
"T" Command went to the appropriate tool position.
Thanks,
Glen.