Passing parameter to a loaded external .SWF

I have this code. Each buttons returns a number that I want to pass as a parameter to the other SWF. How can I achieve this? I never used parameters yet and I'm searching a lot in the forums without success.

Thank you.

import flash.events.Event;
import flash.net.URLRequest;
import fl.display.ProLoader;
var loadClip: ProLoader = new ProLoader();
addChild(loadClip);
F1.addEventListener(MouseEvent.CLICK,btnpressed); 
F2.addEventListener(MouseEvent.CLICK,btnpressed);
F3.addEventListener(MouseEvent.CLICK,btnpressed);
function btnpressed(e:MouseEvent):void{
     e.target.removeEventListener(MouseEvent.CLICK,btnpressed);
e.target.enabled = false;
     e.target.visible = false;
var btnName:String = e.target.name;
var input:String = btnName;
     var pattern:RegExp = /F/;
     var output:String = input.replace(pattern, "");
trace(output);
loadClip.load(new URLRequest("cadeaux.swf"));
}