Since Excel sheets can be converted to XML, he should be able to automate this conversion with some .net base objects.
this shows there are caveats if it contains formulas, but it is a start
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=398481&SiteID=1
there are also utilities people have made
http://www.codeproject.com/csharp/Excel2XML.asp
– weak architect