I loaded a movie clip like this:
// load Home Movie
var loader:Loader = new Loader();
var request:URLRequest = new URLRequest(“home.swf”);
loader.load(request);
// use addChild() to use your movieclip as the Loader object’s container:
container.addChild(loader);
Now, I want to tell that movie clip to do something so I put this:
// play the closing section of the MC inside of the container
container.gotoAndPlay(“closing”);
And, of course it didn’t work in actionscript 3!!!
Any ideas?

I’m a noob, so apologies in advance if this doesn’t work, but your question prompted me to read a chapter in a book that I’ve been meaning to get to grips with, and it seems to work OK.
Try this:
stop();
import flash.display.*;
var loader:Loader = new Loader();
var request:URLRequest = new URLRequest("home.swf");
loader.load(request);
// when the swf has finished loading, we want to run the 'swfLoaded' function
loader.contentLoaderInfo.addEventListener(Event.COMPLETE,swfLoaded);
// this runs when the swf has finished loading
function swfLoaded(myEvent:Event):void
{
// put the swf on the stage
stage.addChild(loader);
// create a movie clip we can control
var myContent:MovieClip = myEvent.target.content;
// play the bit you want
myContent.gotoAndStop("closing");
// change the swf's position (but only if you want to ...)
myContent.x = 120;
myContent.y = 90;
}
Like I say, I’m a noob, so there may be a more elegant way to do this.