Flash - Loading SWF Without Instantiating Document Class?

Is there a way I can load a swf file but not automatically instantiate it's DocumentClass? Instead I want to do something like the following:
protected function mainLoaded(e:Event = null):void {
trace('mainLoaded');
var main:* = this.mainLoad.createClassByName('Main');
trace(main);
}
Where mainLoad is an instance of CasaLib's SwfLoad and createClassByName is the equivalent to
loaderInfo.applicationDomain.getDefinition();
The thing is that when my swf finishes loading I can see it is created, because of some trace calls, although its obviously not added to the display list.