Different Calculations in Pivot Table Subtotal Rows
 

Hello,

I have a pivot table containing sales data in which the products are
in row headers and each month's net sales and cost of goods sold
(cogs) are the column headers.

eg.
January 05 January 04
Product Net Sales CoGS Net Sales CoGS

101 $5000 $2000 $4000 $1800

..
..
..
etc.

I have subtotals after every set of products in every product group
that simply add the Net Sales and CoGS data. I want to make a third
column heading named "Margin %" for each month which is equal to (Net
Sales - CoGS)/Net Sales. So, in each subtotal, I would like the sum of
Net Sales and CoGS but I would like the formula (Net Sales - CoGS)/Net
Sales to appear in the row subtotal under Margin %.

Is it possible to have different calculations in different fields of a
subtotal?

Any info/advice would be appreciated.
H