Help to remove pivots dimensions with set analysis?

[#1]

Hello...  i have a pivot table (see image attached) and the month-year dimension shows the value of the expression horizontally, as columns.   I wanted to integrate a "number of months" slider to display only the month-year columns selected (plus next month)... the columns are still displayed, only the expression values are zero....   How can i remove the month-year columns?

Expression:

=sum({<CalendarDate={'>=$(vMaxDate) <=$(vLastDayPrevMonth)'}>} MatPercentage * MonthlyCurrentPrice )

Variables:

vLastDayPrevMonth=MonthEnd(max(CalendarDate))         (sorry variable name not too descriptive)

vMaxDate=Date(AddMonths(MonthStart(vLastDayPrevMonth),  (vRollingMonths * -1)),'DD/MM/YYYY')

Any ideas out there in QV land?

Thanks in advance,

Bernard

[#2]

Nevermind eh!!   Solved it myself by upgrading my desktop application to the latest...  I love talking to the wall... ;o)