Support for Custom Xml Schemas in Excel 2007
 

Does the new Excel Xml file format (xlsx) support a clean separation of
custom XMl data from the Tables (formerly List Objects) and ranges it is
bound to using an Xml Map? Word 2007 provides this model / view separation
through Content Controls (mapped through XPath to custom Xml). I do not see
this in Excel 2007. My use is to create a 2007 workbook server-side by
simply cracking the xlxs and replacing the custom xml part.