i know this is late, but i just saw this post.

here is code i use to put the frame number of a movieclip (instance name "box2" ) which is nested inside another movieclip (instance name "box1") into a dynamic text box ( instance name "textBox" )

Code:
textBox.addEventListener(Event.ENTER_FRAME, frameNumberText);
function frameNumberText(evt:Event):void
{ textBox.text=box1.box2.currentFrame; }
that should help, or at least give you new ideas!