check out tut #3 from the "Basic Tutorial Section" on my website (just click on the banner at the bottom of my post", this will give you some idea how to create the buttons and highlights.
Also i think that you may be able to take a frame of the MPEG menu directly into photoshop (from within Encore), this can be used as a template then for the positioning of your buttons. once you are done just open up your button folders in photoshop and click the little eyeball of the actual buttons to hide them.
If you are really stuck then PM me with your email addy, i will send you my addy and then you can send me a frame grab of your motion menu... but please have a bash at creating the effect first... B)