Collide with other objects?

Hello. I know how to make it so that a function happens when the object that a collision script (like the one below) is attached to collides with another object, but is there a way to make a script that references another object for both objects? For example, the script is attached to object A and it says something like "When object B enters the trigger of an object with the tag "C" object B = destroyed)? Thanks.

function OnTriggerEnter (other : Collider) {
    if (other.gameObject.CompareTag ("Enemy")) {
       Stats.Life -=1;
       Player.enabled = false;
       Light.enabled = false;
       Invoke("LightsOn", Timer);
      }; 

You've pretty much answered this question yourself:

Reference object A (the script carrier) on either B or C. Make B or C detect collisions/ triggers and send a message/ call a function from A when OnTriggerEnter.

If I'm not mistaken, this is one of the basics of gameController-centered game building, in which you have one central script that all other objects reference and call.