How to change data source of Excel 2007 pivot table to another pivot table?

Hi,

I have a pivot table A created in Excel 2003 with the data source linked to another pivot table B. How do I change the data source of pivot table A link to a new pivot table C in Excel 2007? Can Excel 2007 create/change pivot table with data source link to another pivot table? I can't seem to find any function for that under Excel 2007 Pivot table commands. How do I resolve this? Please help.

Thanks!!