For arguments sake, I take back the depreciation comment, maybe I was a bit hasty! But, the array object can indeed be used to evaluate:
Code:
this.createEmptyMovieClip("holder", 0);
this.holder.lineStyle(1);
this.holder.moveTo(-25, -25);
this.holder.beginFill(0x000000);
this.holder.lineTo(25, -25);
this.holder.lineTo(25, 25);
this.holder.lineTo(-25, 25);
this.holder.lineTo(-25, -25);
this.holder.endFill();
for (i=1; i<=5; i++) {
    holder.duplicateMovieClip("holder"+i, i);
    _root["holder"+i]._y = i*55;
    _root["holder"+i]._alpha = i*20;
}
Try it out and observe the last 2 lines in the for loop affecting the alpha properties and the vertical position of the duped MCs. See?

Cheers