Order unit(s) to attack target of attacking hero .....

Order unit(s) to attack target of attacking hero .....

I have created some units (based of peasant) with ranged attack and more damage, becasue thay dont attack on sight i thought that would be good.

What i wont to do is when my hero is attacking something i wont the units to target and attack the unit the hero is attacking, and then when the hero stops the units stop attacking and so on.

i have a trigger but it doesnt seem to work.

Please Help!!

p.s. this is for a spell i am making for the Arcan Comp.

I hate to not be helpful but I am bound to helping Daelin enforce the rules of his contest. You may not ask for help in creating a spell for the competition, it must only be your own skill. Sorry