Expression in pivot returning 0

[#1]

Hi,

In my script I define month_num1 and month_num3 as following:

year(Date(AddMonths(Date(([Reporting Date]),1)))  * 100 + num(month(Date#(month(Date(AddMonths(Date([Reporting Date]),1))) 'MMM'))) as  month_num1

year(Date(AddMonths(Date([Reporting Date]),1))) 3))) * 100 + num(month(Date#(month(Date(AddMonths(Date([Reporting Date]),1))) ,3))),'MMM'))) as  month_num3

The following expression:

sum({1<ITEM={"Known Mvmt"},forecast_month_num={">=month_num1 <=201309"}>} FTE) is returning the correct figures.

When replacing 201309 by month_num3 in the expression as following it returns 0. The month_num3 is correcty filled in the load.

sum({1<ITEM={"Known Mvmt"},forecast_month_num={">=month_num1 <=month_num3"}>} FTE) is returning 0.

Any idea,

Thanks