Did you intend to send this to the LOC EAD list rather than EADitor?
Excel allows for exporting to XML, so you could conceivably process the spreadsheet in XML form to generate a numerous EAD finding aids. Even better, you can use Google Docs to create and update the spreadsheet and take advantage of Google's API that returns all or sections of the spreadsheet in the form of Atom XML. This makes the processing easier because you don't have to manually export the spreadsheet to XML as you would with Excel. Moreover, the Atom entry for a row includes its modification date, so you can process rows nightly that were modified earlier that day.