In the end, I was able to download the Microsoft Data Provider for this from Microsoft.

The solution is non-Perl, but if you need it, the connection string is of the form:

Data Source=D:\Test.xlsx;Provider=Microsoft.ACE.OLEDB.12.0; Extended P
+roperties=Excel 8.0;
[download]

Edit: g0n - altered link to prevent display of very long url