Have you tried to use the option full accumulation on the tab expression?
EDIT: find attached a sample file
Message was edited by: hencovanee
Full_Accumulation.qvw 136.5 K
you are right, but suppose the case where you have to different fiscalyears and you want to restart the total for each year. like this:
( Store_1, jan/2010,1000, 1000 )
( Store_1,dec/2010,1000, 12000 )
( Store_1, jan/2011,1000, 1000 )
( Store_1, feb/2011, 2000, 3000 )
( Store_1,mar/2011,3000, 6000 )
The acummulation should restart in the mittle.