When you build the release build of the application, you can choose "AIR for desktop" and the app looks exactly like in the emulator.
Otherwise you have to port some of your application components to an AIR project (if you want the full AIR desktop functionality).
I have tried doing what you said the but the resulting air app doesn't do anything. When the air app starts it loads and nothing happens. Are you able to run your mobile app as an air app on the desktop?