Hi,
I have following Pivot Table :

Now For each Month Column, selected dinamically from a prompt I want add a new column with the following formula:
January % = row Category value / Grand Total * 100
The same for other Months.
The output should be like the following:

I've tried calculated elements and other stuff, but it doesn't work. How i can do? It's important the layout.
Can you help me?
Thanks
Giancarlo