mdx to display first day of the week

hi all,

SELECT NON EMPTY { [Measures].[Count] } ON COLUMNS, NON EMPTY { ([Agt].[Name].[Name].ALLMEMBERS * [Date].[Calendar Date by Week].[Week Of Year].ALLMEMBERS * [Date].[Date].[Date].ALLMEMBERS ) }

it displays results as

nov 24,2012

jan 12,2013 etc etc 

but i want the result to be displayed as

nov 19,2012

jan 7,2013

Basically i want the result to be as firstday of the week

how do i achieve this?? please let me know?

thanks in advance