calculated members WHERE statement?

i am trying to figure out how to use MDX and a WHERE statement in the calculated member expression textbox. Every time i try i get a syntax error, and can't seem to find an example anywhere. Is it even possible?

I am trying to make a calculated member (measure) but I need to filter on only a few values of a DIM. I have seen how to write an MDX query and do this, but I need a permenant calculated measure.

Any insights? Thanks

Please keep in mind the difference between an MDX expression (used in defining a calculated member) and an MDX query (which can include a WHERE clause). You can try using Filter() in your MDX expression instead.|||i could never get that to work, i went down the road of making a named calculation and using that in my calculated measure