How to get from external swf to my main movie to Frame Nr.5?

As a student Im working on a main swf (Main.swf). There are many seites with many themes. On each site (Frames 1,2,3,.....25) Theres a button to get to an external .swf. If I`m in the external .swf, there is a button too, to get back (back) to the mainmovie. Now what I wanted to do is, go back from the external .swf to the Main.swf to its Frame Nr.5, when i press the button “back”.
With that Code below I can only get to the mainmovie 1.Frame (its Home).

//Connection to LEVEL1

back.addEventListener(MouseEvent.CLICK,mouseClick3 );
function mouseClick3(event:MouseEvent):void
{
var content:Loader = new Loader();
content.load(new URLRequest(“Main.swf”));
addChild(content);
}

What should I add the code to make it work?
Many thanks for helping proposals,
Judit