_Slowly_ draw a (curved) line?

Hi folks

Here’s the effort simply displayed: http://www.mountcrumpit.com/DoorSwing.swf.
it uses curveto to show the arc of a doorswing.

I’d like the drawn arc instead to appear/trail along the leading edge of the door as the door swings open. Guide Layers AS2 led me to tweening AS3 class but the beginning and end objects weren’t right. Am I in the wrong place? This seemed somewhat straightforward but perhaps I’m searching for the wrong keyword(s). Can some one put up a direction for me?

thanks. bryan