You can use OPENDATASOURCE in a query e.g
SELECT *
FROM OpenDataSource( 'Microsoft.Jet.OLEDB.4.0','Data Source="C:\TestJoins.xls";User ID=Admin;Password=;Extended properties=Excel 8.0')...Sheet1$ AS s1
INNER JOIN OpenDataSource( 'Microsoft.Jet.OLEDB.4.0','Data Source="C:\TestJoins.xls";User ID=Admin;Password=;Extended properties=Excel 8.0')...Sheet2$ AS s2 ON s2.KeyID=s1.KeyID
Where the first...