When you design Excel templates use the Excel Template Builder for inserting fields and repeating groups to your template.
When the Template Builder inserts a field or repeating group it creates a mapping between the data and the spreadsheet and writes the mapping to a hidden sheet called the XDO_METADATA sheet. The Template Builder creates the hidden XDO_METADATA sheet the first time you insert a field or repeating group.
To view or update the XDO_METADATA sheet unhide the sheet. To add calculations or more advanced functions, enter the XSL functions directly in the XDO_METADATA sheet using the named mappings created by the Template Builder. For more information about template-data mappings, see Understand Excel Template.