Attach class to a movieclip created with 'createEmptyMovieClip'

I know it is possible to attach a class to a movieclip that exists in the library by checking 'Export for ActionScript' and specifying an 'AS 2.0 class' for that symbol.

I would really like to know if it's also possible to attach a class to a movieclip that was created by using the 'createEmptyMovieClip' method. Does anyone have an idea?