Target duplicated mc's

(bare with me only venturing into intermediate AS)

OK! building a spaceship game where you have to blow up enemy fighters. The enemy fighters are duplicated off a mc with the instance name of “enemy1”. The following code is used

for (i=2; i<=numEnemy; i++) {
L1.enemy1.duplicateMovieClip("enemy"+i, i+10);
}

All is working ok, hitTests work great, BUT i want to have it so that each fighter must be hit by lets say 4 bullets before exploding. More realistic.

I read duplicated movieclips dont store variables from their parents, and it has me confused on how to accomplish it. I thought of storing variables on _root in relation to the max enemy fighters i have at one time, then adding a point on each time a bullet hit the enemy. Once hits 4, explode enemy, and reset variable. But i cant seem to work out how to target the duplicated moveiclip.

Can someone please help, ive been looking at it so long im even starting to confuse myself