Thanks steve

Do you have any idea of why Cube Editor -> Insert -> Calculated Cells menu doesn't exist in my machine?

I've been reading some docs to try this, but that I've found no way to get it. Ex. this picture

I don't have that menu option in my machine 

On the other hand: I've tryed Custom Rollups, but this seems to affect ALL measures, I need only to apply rule to one single measure.

Is there something you can advice?