Is it possible to do a Pivot table with dynamic dimension

[YJ_SG]

I am exploring whether Qlikview can do a pivot table manually.

Defined two table, one is to replace Pivot Row (ReportMonth), the other to replace Pivot Columns (ForecastMonth). And use expression to calculated pivot table.

I tried few expression, the first one give me sum all of forecast month.

=SUM({<[Forecast Report]=P(ReportMonth)>}[Forecast Qty])

How to separate it by Forecast Month?

I tried below one, not working

=Aggr(SUM({<[Forecast Report]=P(ReportMonth),[Forecast Month]=P(ForecastMth)>}[Forecast Qty],ForecastMth))