Calculated subtotals in rows

I have two tables :

Mapping table : 

Here is the data table :

Using the data table in conjunction with the mapping table, I need to change Funct_Area in data table and create a P&L schedule so that it looks like this :

As you can see the P&L schedule has row items that correspond to what is available from the mapping table in the fields FA Gr L2  (Net Sales, RnD, and SGnA) and FA Mg 01 (Distribution Margin) and FA Mg 02 (Division Margin).

Distribution Margin is just the sum of Net Sales, Cost of Sales, OMC, and Other COGS.

Division Margin is just the sum of Distribution Margin + RnD +SGnA.

So the data table should be mapped to the mapping table using the fields FA (from Mapping table) and Funct_Area (from Data table).

How can I combine elements of two different columns to change Funct_Area so that it has Net Sales, Distribution Margin, RnD, SGnA, and Division Margin?