AddChild and Variable in MC Class

So basically Im trying to assign a varible movie clip to the stage based off a number in my XML file. Im successful in extracting that number, Im just unsuccessful in creating a new variable MC name in AddChild. Ive been searching the internet for an answer and have been coming up blank.

Anyone have any ideas?

Here is my code:

var star1Num:Number =[index].cityprice.starcount[1].toString();
    star1sp.y = 70;
    star1sp.x = -10;
    star1sp.addChild((star + [star1Num]));