See a doc I have published on LOAD: http://community.qlik.com/docs/DOC-5698
1) you need to sort the rows (ORDER BY)
2) you need to test that you may do the cumul: if(peek('A')=A And peek('B')=B, OK I can compute, I cannot compute)
3) you use rangesum()
I sorted (Order By) the list and managed to calculate a cumulative sums by adding a following row:
if(peek('Product')=Product And peek('Version')=Version, Rangesum(Amount, Peek('CumulAmount')), Amount) as CumulAmount,
Any ideas on how to accumulate only 3 values?
or how to pick cumulative value from rowno() - 3? so it could be subtracted from cumulative value