Excel导入SQL2005报错

[leitnt]

' 测试制单日期是否有误
   sql = "IF EXISTS (SELECT * " & _
            "FROM (SELECT isdate(制单日期) AS dt " & _
                    "FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0', " & _
                          "'Excel 8.0;hdr=yes;Database=" & Trim$(txtPath.Text) & "', [Sheet1$]) Rowset_3) out1 " & _
            "WHERE (dt = 0)) " & _
         "SELECT 0 as flag ELSE " & _
               "SELECT 1 as flag "
   Set ado = ExecuteSQL(sql, False)
   If ado!Flag = 0 Then
      MsgBox "Excel表中“制单日期”有错误项！", vbInformation
      GoTo Finish
   End If

报错：链接服务器"(null)"的 OLE DB 访问接口 "Microsoft.Jet.OLEDB.4.0" 返回了消息 "未指定的错误"。