[Хемуль]

С событиями типа так можно:

var path:String = "a.swf";
var request:URLRequest = new URLRequest(path);
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loaded);
loader.load(request);
 
function loaded(event:Event):void
{
	loader.removeEventListener(Event.COMPLETE, loaded);
	addChild(loader);
	var loadedClip:MovieClip = loader.content as MovieClip;
	loadedClip.gotoAndStop(3);
}