Tim_pbjp Hi Tim, i know exactly why you want this but why bother spending all that time and effort of programming something that is so easy to do on the run . Perhaps you don't use a remote is one reason , and you don't want to touch the screen is another, but if thats the case ST3 is not meant to be an audio editor it is just a bloody powerful player that allows you to loop segments of songs and repeat these sections with absolute ease as you desire on the night, but you need to use remotes or touch the screen, without those two things you need to then create your song of how you want it in a DAW.
If you do use remotes then its as easy as a button push to repeat a section as many times as you like and another push to release the loop , but not only that if you only want one repeat hit the appropriate button and you only have one repeat, but if you feel the audience wants more hit it again and you have another single repeat you can keep doing this till the cows come home with ease on the night and not be fixed to a pre programmed loop number selection that will screw you over most of the time because you wont remember all your selections you made for all your songs, so to me your idea just creates confusion not help on stage.
Sorry for the long explanation but i just wanted to point out the negatives, and save you lots of time in editing.
Cheers Damir