Using Cube function to add two measures together

I am using Excel 2010 so I cannot add a calculated field to an OLAP Pivot. Is there a way I can use a cube function to do the same.

E.g. to have a single field that contains the combined value of two Measure fields

Something like =CUBEVALUE("Connection","{[Measure].[Cost Price] + [Measure].[Mark up]}")

I'm not clear about what you are trying to do.

Can you upload a small sample file that shows both the data you are working with and results you desire, mocked up if necessary by hand typing them in?

Given two measures I would like to present a single calculated measure that adds the the other two together.
So, for example, if my cube has two measures "Cost Price" and "Mark up" I would like to create a cube function that will add the two together and and present this as single measure "Selling Price".

See attachment for example