Events and Inner MC's that ruin the target

I have a problem that should have an obvious-enough solution but alas, I do not know it.

Here are snippts of what’s going on…

 
npcObject[npcId].addEventListener(MouseEvent.MOUSE_OVER,mouseOverNpc);
 
public static function mouseOverNpc(event:Event) {
 
   id = event.target.objectId;
   $root.ui.npcName.textColor = getColorForHostility($npcObject[id].hostility);
   $root.ui.npcLevel.textColor = getColorForHostility($npcObject[id].hostility);
   $root.ui.npcName.text = $npcObject[id].name;
   $root.ui.npcLevel.text = $npcObject[id].level;
  }

Based on the line:

id = event.target.objectId;

You can probably guess that i created an ‘objectId’ property on the movieClip to access other properties of that MovieClip. This works just fine in most cases however if I am referencing a movie that has an inner MovieClip (such as a tween) it throws an error.

The error states that: A term is undefined and has no properties.

The reason this error occurs is that the e.target.objectId does not exist on the inner tween effect, only on the outer clip. If the user mouses over a portion of the tween (which could occur often) then the error pops up.

Is there any way to reference only the outer movieClip as my target or something that would give similar results?

The other alternative is to find a means to pass new args into the movie that does not use e.target however I couldn’t find much information about this either.

Any help would be appreciated.