Speaking about possibilites with Office and XML...

You should check out the Excel XML Writer Library and the Excel XML Writer Library Code Generator created by Carlos Aguilar Mares. Carlos downloaded the Office 2003: XML Reference Schemas, ripped the bones of the Excel 2003 XML Reference Schema, and created a C# library that allows you to generate Office 2003 XML Workbooks. If want to see the power of Excel and XML in action, this is a MUST see. This tool is more than fantastic!