Using swf as movieclip how do I need to change AS?

This should be easy but I have already spent too much time on it, so I am going to throw the question out here. I had an swf that was working fine, it contains an animated mc that is actually placed on the main timeline along with this code to further animate the mc:

moveMe = function() {
this._x -= this.speed;
if(this._x<0) {
this._x = 550;
if(this._x>550) {
this._x = 0;
for (i=0; i<100; i++) {
nm = “shield” + i;
grow_shield.duplicateMovieClip (nm, i);
d = Math.random()*2;
if (d<1) {
_root[nm].speed = -3;
_root[nm].speed = 3;
_root[nm].onEnterFrame = moveMe;
_root[nm]._x = Math.random()*840;
_root[nm]._y = Math.random()*475;

You can see the swf here.
Now, what I would like to do is make this file into a movieclip so that I can use inside another fla without using a loadMovie command…I just want to use attachMovie, etc.

I have tried placing the clip and the code one level down (creating new movieclip symbol) and now all it does is play the animated clip that is actually placed on the timeline over and over…here is the example
I know it has to do with the paths…I need _root or _parent or to change the this reference somewhere, I just can’t figure out where.

Any tips would be appreciated!