The advice I provided in the previous post is still valid - the Calibre forum is not an ePub authoring forum. Queries regarding achieving this are better directed
to the appropriate place.
I'd also recommend querying ePub working group themselves - they're really busy adding multimedia/interactivity to ePub, I'm sure it won't hurt to remind them that a lot of basic stuff that works in printed media still needs to be solved for ebooks before we start adding movies and javascript.