Edmond Woychowsky walks you through his process, including all the necessary sample code, to convert an XML file to an Excel spreadsheet.

TinyWow can split an Excel file if you want the XLSX file to end up as multiple files. That same site has an Excel to XML converter, and others that can save the file to PDF or CSV.

You can create XML data from a Microsoft Excel 2003 worksheet or workbook, but you'll need to do some manual steps to get the data to conform to valid XML format.