This can be done simply by using a progressBar and the loader class.
import flash.display.Loader;
import fl.controls.ProgressBar;
import flash.events.Event;
import fl.containers.UILoader;
var myLoader:Loader = new Loader();
var my_pb:ProgressBar = new ProgressBar();
addChild(my_pb);
myLoader.load(new URLRequest("http://www.SomeImageURL...."));
my_pb.source = myLoader.contentLoaderInfo;
myLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, completefunction);
function completefunction(e:Event):void
{
removeChild(my_pb);
myLoader.content.width = 200;
addChild(myLoader);
}
To have the movieClip symbol use different images, we just need to add a string variable to the movieClip and pass the url to that variable each time we create a new instance of that.