Override XML Mapping?

[VtQuest]

I know very little about XML and mapping. I had set up an Excel spreadsheet using an XML map to receive data for a report. Unfortunately, some fields were added to the original data form and when I try to add the new fields from the XML map, I get the message "The operation could not be completed because the result would overlap an existing XML mapping." So, I have deleted all of my old spreadsheets with this mapping and have attempted to create a new excel spreadsheet with the new fields. I keep getting the same response. Is there anyway to override this message? I have no idea what to do. Please reply in simple terms. Thank you.