MDX Where Equivalent

I have this MDX query:

SELECT NON EMPTY { [Measures].[Reflex Tests] , [Measures].[TOTAL RAN] ,
[Measures].[Incomplete] } ON COLUMNS,  
 {
   ( [Tbl ECONN ASSAY].[Assay Name].[Assay Name].ALLMEMBERS,
   [e Conn Instrument].[Salesman Code].[Salesman Code].[116],
   [e Conn Instrument].[Salesman Name].[Salesman Name].ALLMEMBERS,
   [e Conn Instrument].[CUST NO].[CUST NO].[131326],
   [e Conn Instrument].[Customer Name].[Customer Name].ALLMEMBERS )
}  ON ROWS  
  FROM  [Detail Usage] WHERE {  [ALL TIME].[TIME SID].[20070101] : [ALL TIME].[TIME SID].[20070301]  }

I would like to modify it to exclude some Assay Name values. The in T-SQL I would use the WHERE clause something like this:

WHERE AssayName NOT LIKE '%whatever%'

What is the MDX Equivelant syntax for this? Can I filter out certain assay names from the MDX result set somehow?