How do I save an Excel 2007 file in "OOXML" (xml text) so that I can modify it in code?

Question

I made an Excel file with data on tab 2, and a chart on tab 1. This is for a web-portal where investors can download the excel document with ubber graphics and the like, but with their data.

So, the 'simple' fix in my mind is to save the Excel document as "OOXML" and just replace the data items. However, it seems that the document is encrypted (at least... not readable in notepad).

How do I get to where I need to go here?

Thanks,

Answer 1

Found my solution... using the Office Open XML SDK and googling / playing with it for a while.