Hi Steve,
In the meantime I found another syntactical solution on the web.
Here's an example.
WITH
SET [TCat] AS
TopCount([Product].[Subcategory].[Subcategory],10,[Measures].[Sales Amount])
MEMBER [Product].[Subcategory].[Other] AS
Aggregate([Product].[Subcategory].[Subcategory] - TCat)
SELECT { [Measures].[Sales Amount] } ON COLUMNS,
TCat + [Other] ON ROWS
FROM [Adventure Works]
;
Franky L.