Decrease Reps in a Workout Repeat

I tried to create a workout that my exercise group is doing this week but couldn't the way I wanted to do it.  The work is 3 exercises repeated.  It starts with 10 reps each and on each repeat, the reps decrease.  If I were to create this workout specifying the reps it would include 30+ steps. 

If I use the repeat function to simplify it, I cannot specify for the reps to decrease on each repeat.  I could change it to lap button press instead of a number of reps, but thought it might be useful if Garmin would consider adding more flexibility to how workouts are created.