Modifying shapes through actionscript

Hi everybody,

I’ve got an idea for a game, but first I need to know if I this can be done with Flash Actionscript. Offcourse I’ve Googled, but haven’t found any answers on my question:

Can I modify shapes through actionscript something like this;

before: -----------------------------

after: -----------______/---------

So I want to cut something out of a current shape (prolly a circle out of a rectangle)…

Can you guys help me ? Or should I state my problem more clearly ?

TIA,

Solice