So what's the question? Perhaps: "how do I have buttons in my Flash file cause the Director host to navigate to a different frame in the score?"
Yes, indeed, the host program is Director and all the pages should be made in Director except the Main Menu page (the first page) which is an interactive flash file.
This flash file contains some buttons which are supposed to lead the users to the other pages of the multimedia cd. But now I don't know how to import this flash document into the Director, so that I can control the interactivity of the animation by using lingo, and make the links to the other pages which are already done in Director.
You use the getURL() command in Flash to tell Director what to do. Either: