Controlling the sound of the external loaded SWF

Question

I  have a Loader that loads external SWF. The external SWF has sound.
I'd like to stop, pause and play the sound.
How?
Please help me !
var loader:Loader = new Loader();
loader.load(new URLRequest("moora.swf"));
addChild(loader);
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, on_loader_complete);
var mc:MovieClip;
var st1:SoundTransform = new SoundTransform();
var sn:Sound = new Sound();
var ch:SoundChannel;
var offset:Number = 0;
function on_loader_complete(e:Event):void
     mc = MovieClip(loader.content);
     play_btn.addEventListener(MouseEvent.CLICK, on_play_btn);
     pause_btn.addEventListener(MouseEvent.CLICK, on_pause_btn);
     stop_btn.addEventListener(MouseEvent.CLICK, on_stop_btn);
     trace(mc.totalFrames);
function on_play_btn(e:MouseEvent):void
     mc.play();
     st1.volume = 1;
     mc.soundTransform = st1;
function on_pause_btn(e:MouseEvent):void
     mc.stop();
     st1.volume = 0;
     mc.soundTransform = st1;
function on_stop_btn(e:MouseEvent):void
     mc.gotoAndPlay(1);
mc.soundTransform = st1;
This only mute the sound only and the sound is still runnung.

Answer 1

The loaded external SWFs are AS3. The sound is on the timeline. Some SWFs use loaded sound, Here is its code:
var snd:Sound = new Sound();
var req:URLRequest = new URLRequest("moora.mp3");
snd.load(req);
So, how can I control the sound (Stop, Pause, resume).