if I understand your data set correctly, you might also consider not trying to filter the data but rather conditionally display and then use a formula fields to get your sum
It really depends on what layout and other requirements are in the report.
The sum (for a row) can be accomplished with 1 formula
(NETPERD1)+
(if {?Period}>1 then NETPERD2)+
(if {?Period}>2 then NETPERD3)+
(if {?Period}>3 then NETPERD4)+
(if {?Period}>4 then NETPERD5)+ ...
Edited by DBlank - 27 Nov 2013 at 3:49am