Yes, the Flash object supports this. From JavaScript you can stop and start the movie, set variables,tell target, etc.

The Macromedia technote #13945 describes settings variables. The title of this technote is "Scripting Methods Supported in the Flash 4 Players". If you search for these words at http://www.macromedia.com/support/flash/ you should find everything you need.

Good luck!
-Geoff