It's not that hard.
1.) Start Flash
2.) Create new Symbol->Movie (this will be your animation on roll over)
4.) Create new button, there will be 4 frames to a button,
The first is the static image (just import it, or make a new one)
The second happens on mouse over (put your movie from 2 here)
The third is shown when the mouse is clicked, this should be the movie, the original image or something new
The last is just to define the "hit area" make this a solid sqaure the size of the other frames of the movie.
5.) Place your button in the main frame of the main scene of the movie file, and then add the actionscript (if you don't know actionscript use the easy selection interface) [red]onButtonRelease{ goToURL("
[/red] (or whatever the equivelent is now) to the button.
The real question is why not export the roll over image as a JPEG and leave it a CSS rollover.
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