opendatabase Excel 9.0

I am trying to convert an Excel-2000 sheet to a table in an Access-2000 DB. I have written these lines of code:

...
Set oDB = OpenDatabase(sXLSPath, True, False, "Excel 9.0")

If (Err <> 0) Then
MsgBox [Err.Description], vbInformation
On Error Resume Next
Set oDB = OpenDatabase(sXLSPath, True, False, "Excel 8.0")
End If
...

and this is what I get in the message box:

[Impossibile trovare ISAM installabile]

that is "it is not possible to find an ISAM to install". Why?

I have Office 2000 installed, dao360.dll active, msexcl40.dll active...

What else do I need to activate Excel 9.0 drivers instead of Excel 8.0 (my sheet is in fact opened as an Excel-97 sheet).

Thanks for your help. I have tried to find a solution at Microsoft support pages without success. C.Bartolomeo