How to exclude one week from this year and one week from last year

Hi,

I have a mdx query which is something like this 

with
Set [Year]AS ([Fiscal Date Calculations].[Date Calculation].&[Selected Date])
SET [LYYear]AS ([Fiscal Date Calculations].[Date Calculation].&[LY Day])

member [TY Sales]              as SUM([Year],[Measures].[Net Sales Dollars])
member [LY Sales]              as SUM([LYYear],[Measures].[Net Sales Dollars])



SELECT 
{[TY Sales],[LY Sales]}

 ON COLUMNS , 
non empty{
  {
[Financial Location].[Location Segmentation].&[1 Premiere],
[Financial Location].[Location Segmentation].&[2 Grow],
[Financial Location].[Location Segmentation].&[3 Core]
} 
*{[Financial Location].[Location Center Type Code].&[Lifestyle],[Financial Location].[Location Center Type Code].&[Mall]}
*{[Date].[Fiscal Year].&[Year 2012]}
}on 1  FROM [EDW]

The values i get are for whole 2012 and 2011 years.

Now,i want to get TYSales as year 2012- week 53 and LYsales and Year 2011-Week1 of 2012( which is sync with 53 week of 2012).

Can some one please help me with this.

Thanks.