TomTom, you made it complicated with it being on a Pop-up Layer!

Here is a solution: JS - Restart Pop-up Presentation.xar

The green control has to do two things together, restart and open. Xara is not built for this so I had to code it as JavaScript into its Link.

The numbers 1 - 7 show how to start at any slide position, even when the Pop-up is closed; you need to press the blue control.
The number call the presentation page but render it inside the Placeholder - look for 'acorn' in the Link dialog. This allows you to control an IFRAME externally.

I did not animate the presentation.

Acorn