So I want to share what I've learned on my blog :
private var htmlObj:HTMLControl = new flash.html.HTMLControl();
html.width = 100;
html.height = 100;
Simple as the beer !
They told that HTMLControl class is like an IFRAME but it's hosted by Flash content.
The HTML content will be rendered as root content in a window with no browser chrome !
Stay tuned, I've more lessons to publish ;)