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.

The XML editor lets you create an XML Schema definition language (XSD) schema from an XML document. The XML file determines how the schema is generated in the following manner: - If the XML document ...

When uploading and opening an Excel file with custom XML in Office on the web and then re-downloading it, the schema information should not be removed from the custom XML properties in the document.