Document Class and Custom Class Communicating Question

Okay, so the website I’m work on has the document class Main. Within this website I have a movieclip on the stage which I built a custom class for its functionality and I linked this movieclip to this class to make it work. There is no reference to this movieclip or class in Main.

Now, I need to communicate between these two classes. Can I do this? Can I dispatch an event from the custom class linked to the movieclip and have the document class listen for an event? How?