An Example of HITPRCNT_PROG:

1) Type: HITPRCNT_PROG
2) Args: 25
3) Commands:

The HITPRCNT_PROG is triggered if the mob is fighting and the
mob's lifetotal (hitpoints) is less than ARGS's percent value.
I.E: If a mob is fighting a player, and the mob's lifetotal
falls below 25%, then the trigger will be executed.
Tips:
If you use multiple HITPRCNT_PROG, start with the lowest percent
and work your way up.  This will allow for multiple HITPRCNT_PROG
to be used at different levels.

If you don't know what ARGS is, help args.