Override MovieClip's parent and stage properties

Hello,

is there a way to override a MovieClip's parent and stage properties?

In a custom class extending the MovieClip class we can override the get parent() and get stage() methods. But is there a way to do it to existing MovieClip?

I mean I have an external swf content (loaded) and assigned to a movieClip. But now, how can I assign the loaded MovieClip to my custom class, so that it "doesn't see" the parent and stage properties?

Or can I override functions of existing classes?

Sth like:

override public function myMovieClip["get parent"]():DisplayObjectContainer

{

     ...

}

Please help me with it. I just need to prevent a loaded MovieClip from having access to the main movie's stage.

Thanks!