Depending on the PPT version, there are various ways you can run it directly in the browser. The methodology changed from Office 2007 to Office 2010.
Office 2007, you save it directly as HTML.
Office 2010 the steps change, but you can still do it.
However....I don't think either of those allows full interaction, as in button pressing within each slide. You get forward and back via nav buttons.
I am using PowerPoint 2007 but can easily get other version. Although I did save it as an HTML file it didn't allow for the interaction that is required (like you have said). Do you think what I am asking for is possible?