One other possibility to think about: What does Excel offer you that you wouldn't be able to get via a basic web form? Another way to state the question is: How might the use of a web form simplify and/or enhance the project?
in reply to XML and Databases and Excel, Oh My!
(Or, depending on your particular situation, maybe a basic Perl/Tk, Perl/Gtk or similar GUI app would be preferable to a web app.)
The point would be to get the end users into direct contact with the database, rather than bothering with external intermediate files. You could even add a table to the database to log all updates, so that you keep a revision history and can roll back if you want.
Depending on lots of factors, there are good reasons for both approaches (spreadsheet files vs. direct DB access).