YTD Value Calculation

Hi Everyone,

I'm trying to calculate YTD value in back end

I have DSO with posting date granularity and I'm trying to load data into a  Infocube at fiscal period level but I want YTD calculation as well.

DSO :

Company Code GL Account Fiscal Period  Posting date Amount

10                    12000           2011.01         1/2/2011      25

10                    12000           2011.01         1/3/2011      25

10                    12000           2011.01         1/4/2011      25

10                    12000           2011.01         1/5/2011      25

10                    12000           2011.01         2/2/2011      25

10                    12000           2011.01         2/3/2011      25

10                    12000           2011.01         2/4/2011      25

10                    12000           2011.01         2/5/2011      25

Infocube:

Company Code GL Account Fiscal Period   Amount        YTD

  10                    12000       2011.01          100               100

  10                    12000       2011.02          100               200

Can you explain and how to do the YTD calculation in Infocube level not yet Bex level

Thanks in advance.