Well, the process is quite simple. Not much experience required. Even simple gotoAndPlay(), gotoAndStop(), stop() functions could help you to make it. Here's a primer that will teach you to make a simple drop-down. http://www.kirupa.com/developer/mx/dropdownmenu.htm.

You could modify it your own way and get what you want.

Of course if you have a little more experience with flash and actionscript, you could make flexible and reusable menu with better features, that could be better animations or importing menu items from XML.