SSAS calculated measure with where clause (MDX)

Question

I am trying to create a calculated measure to calculate average with something like a where clause in VS2012 BI.

CREATE MEMEBR CURRENTCUBE.[Measures].[Sem Average]

AS [Measures].[SG_Sem] / [Measures].[Counted_Rows] <-This is already working

WHERE [Measures][Kenn] = 'BE' <-something like this is missing

THX

Answer 1

CREATE MEMBER CURRENTCUBE.[Measures].[Sem Average]

AS 
  ( 
     ([Measures].[SG_Sem] / [Measures].[Counted_Rows]) , [Measures][Kenn].&[BE] )
  )