Change Health of a duplicated enemeis

i have a lot of enemies, that are duplicates from each other.
(Enemy1, Enemy2, Enemy3...)

and i have a script that selects the nearest enemy as target.
and i have an attack script that deals damage to the enemy:
AIEnemyHealth.CurHealth -=15;
(AIEnemyHealth is the health script for the enemy)

here is the problem:
i can only attack the original enemy, not the duplicates.
and if i attack the original enemy, all 3 health bars show damage.

i guess i need to make the target select script the attack script what target is selected,
and then only change the targets CurHealth.

but i have no idea how to do that.

everything is in c#!