Percentage of Base with Report Studio

[skocet]

Hi all,

I'm working on a financial report (Report Studio 8.3) with a MDC cube as datasource.
I want to display a list of accounts, for each account an amount and into a third column, a percentage of my amount based on a specific account :

Account | Amount | %Amount
-----------------------------
A1        |    100   |    50%
A2        |    200   |   100%    <- This account must be concidered as the base of my percentage
A3        |     50    |    25%
A4        |     40    |    20%
A5        |     20    |    10%

Any ideas ?

Thank's in advance

Regards

SK