Add Excel Workbook to PPTX file

[someone]

I am writing n application to automate producing charts in Powerpoint 2007
using Excel 2007.

Does anyone know the VB / C# code to enable me to embed the associated
Excel workbook in the PPTX zip file - so that it is saved with the archive
just like the Excel workbook that goes with 'normal' Powerpoint 2007 charts
and is saved in the PPTX file?

Or - alternatively - how do I access the embedded Ecelwork book so that I
can use that for my charts?

Any help or pointers greatly appreciated.



Thanks.