To analyze data from your BW system with Microsoft Excel 2007, you need to connect MS Excel to your BW system.
You have installed the current dll files for Simba OLE DB for OLAP. You can find these files and all relevant details in SAP Note 1134226.
Make sure that the spreadsheet that is open is not in compatibility mode. If it is, you can only use the functionality from MS Excel 2003 and lower.
You have connected your BW system to Microsoft Excel 2007. Your spreadsheet now contains the pivot table report on the left and the pivot table field list on the right.