SSAS Calculation how to compute or create Dimension

Hi everyone

I need some help with MDX as I am trying to create another dimension using existing dimensions in the cube.

I have datetime dimension and TimeZone dimension. What I want to do is somehting like this in sql

NewDimension = DateAdd(Minute,minutes, UTC) from TimeZoneDimension where datetime dimension > Attribute1ofTimeZoneDimension and datetimedimension < AttributeofTimeZoneDimension

I need help in writing MDX for this, I need to compute another dimension based on whats in datetime dimension (Add minutes) filter based on datetime dimension.

Thanks

-Sarah