Width of a movieclip without creating an instance

Hi there. I’m adding skins to the Button component and I’m wondering if there’s a way to grab the width of a movie clip without creating an instance of the movie clip on the stage.

Here’s my code:

initObj = new Object();
initObj.falseUpSkin = "movSpinButtonUp";
initObj.falseDownSkin = "movSpinButtonDown";
initObj.falseOverSkin = "movSpinButtonOver";
initObj.falseDisabledSkin = "movSpinButtonDisabled";
initObj.label = "";
initObj._x = gui.getSpinButX();
initObj._y = gui.getSpinButY();
initObj._width = *** HOW TO GET movSpinButtonUp's WIDTH ***;
parentMovie.createClassObject(mx.controls.Button, "spinbutton", parentMovie.getNextHighestDepth(), initObj);

I want to be able to get the width of movSpinButtonUp and assign that width to my new button created with createClassObject() without hard-coding a numeric value.