PowerPoint 2003 XML Schema and MHT files

[Guy007]

I have an ASP.NET application, which successfully integrates with Excel,
Visio, Outlook and Word 2003. This I did using the XML schemas for these
products.

I now need to integrate with PowerPoint 2003, such that I can do the
following tasks:
1) Open an MHT file in PowerPoint (all contents - text and images, placed in
one slide)
2) Build a PPT XML file programatically, which can be opened in PowerPoint
2003.

The problem is that:
1) When I try opening an MHT file in PowerPoint, it comes blank (except for
any images found in the html page)
2) I cannot find an XML schema reference for PowerPoint 2003.

Can anyone please help me out with these two issues!?

Thanks!

Daniel