How can I transform the actual glyphs of a TextField? If I use scaleX or transform.matrix.scale, the text box shrinks, but the text itself stays the same size.

I'm trying to do something like this:
textField.scaleX = textField.width/textField.textWidth;
to force a String to fit into a specified area, like in Illustrator. I want the width to be whatever I set it to, but the whole String needs to scale to fit in the box.

Thanks.