What is equivalent to "acSpreadsheetTypeExcel9" in 2007 i.e .xlsx

[mls via AccessMonster.com]

I have a button when clicked does the following ..

DoCmd.OpenQuery "qry_ExpToXl_LotNo"
DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel9, "Qc_details", "c:
\work\QC_Details.xlsx", True

transfersheet fails if I use .xlsx , i.e I could not open the spreasheet
after creation, but it works fine if I give .xls extension.

Any thoughts?

Thank you