SET Analysis expression help

[#1]

I want to count how many items I got in stock this month compared to what was in stock at the same time last year.

So something like this:

( {<MONTH={$(vCurrentYearMonth)},MONTH = {$(vLastyearMonth)},ItemNumber={'76319','76329'} >} Items) plus the big problem

I want to count this month 27 days of oktober 2014 and 27 days oktober 2013

[#2]

sorry guys

I cant make i work properly

I think my explanation is wrong

I´m going to make a new thread