Thanks so much! That did the trick. I completely missed the plugins:
plugin::CheckDist(entity, distance);
plugin::CheckDistBetween2Ents(entity1, entity2, distance);
The code for the spawned adds now works as intended:
	Code:
	sub EVENT_AGGRO {
   quest::shout("$name!!!");    #Shouts the name of the player that better start running
   quest::settimer("distance", 1);
}
sub EVENT_TIMER {
   if ($timer eq "distance") {
     my $target = $npc->GetTarget();
     if(plugin::CheckDist($target, 21)) {
          $npc->SpellFinished(732, $target,0); #cast Ice Comet on target if it is within 21 units of distance
          quest::depop();
     } 
   }
}