Calculation of totals using fox formula

Hi experts;

This is a sensible question and it is needed for going live next Monday.

In the InfoCube I have the following data:

Material \ Month     Jan     Fev     Mar     Abr

          A              10      5      8        4

          B              20     15     18     14

          C              30     25     28     24

          D              40     35     38     34

          E              50     45     48     44

         TOTAL             150     125     140     120

Using fox formula, how can I calculate a distribution key (using the following formula)?

Distribution key (A, 1) =

value of material A for Jan /Total of materials for Jan                    

DK(A,1) = 10/150 = 0,066667

This distribution key must be for all the months.

Using variables, I already “get” the individual value for material:

DATA MONTH TYPE 0FISCPER.

DATA MATERIAL TYPE 0MATERIAL.

{MONTH, MATERIAL, 0AMOUNT}

But how can I “get” the total of the month for all the materials?

If not fox formula, there is any other way?

Best regards;

Ricardo