Dynamic Variance calculation in Bex Report?

Hi All,

Calender week is with selection option in the variable of Bex report.Ex: User can enter two calender weeks.

In the out put we will get two columns( Calender weeks ) with respect to the key figure.

Is there any way i can get the dynamic variance calculation in the report between two Calender weeks as a extra column.

Thanks,

Ramnaresh