A reader sent me this question:
Is it possible to control the PowerPoint presentation with Flash? The opposite of this works, as can be seen on this link on the Microsoft site (link no longer exists). I would like to make Flash navigation to advance slides and control the PowerPoint animation.
The short answer is that this is not possible!
But there’s a workaround, and a rather long workaround. You can get your PowerPoint content into a product like Wildform Flair, and then add controls to the animations from within the program–and then export this as a Flash SWF movie. Not exactly what you are looking for, but just another option.