Help to SET Analysis - get past 4 weeks

[#1]

I want to show the last 4 weeks sale in a pivot table and cant just figure out how to.

Of course I can show the field weeknumber and make a count sold items.

But I dont want to filter at all.

Is there a way to make a SET Analysis with something like this

COUNT( {$< weeknumber = { '<= lastweek', lastweek-1, lastweek-2, lastweek-3 } >}solditems)

I know its wrong but I hope it shows what I mean

[#2]

thanx both

I got it working

I didnt write the variable right, - missed the =

after that all variables worked and I´m happy

best regards