External SWF -> Please Help

I know how to load an external swf like:

I have container.swf that has this code :

var request:URLRequest = new URLRequest("content.swf");
var loader:Loader = new Loader();
loader.load(request);
addChild(loader);

But I want the content.swf to be able to affect the “root” timeline of the swf that loads it.

what I’m doing is loading a menu in content.swf , I want to be able to click on a place on that menu and run a function in container.swf.

I’ve never been able to understand how loaded swf’s work, can somebody help me/explain how these things work together ??