Need Help Subtracting data from the same column in a matrix table

Hi there! 

I have a column named "ACCT" in my table that contains rows of portfolios and indexes. I am using the matrix table visual to compare various data points between the portfolio and index. I want to compare the data points in all of the columns between a portfolio and and index in the ACCT column by just subtracting the portfolio from the index. I filtered all of the visuals in the report by the portfolio and index that I want to show. Is there a scalable way to create a third column that will always subtract the portfolio from the index? So the subtraction will always occur between the 2 filtered ACCTs in every report. I want to create 50 reports with dozens of visiuals so I dont want every field to have a separate measure that's hardcoded for the difference between the portfolio and index. In my visual below, "ADRREP01" is the portfolio and "ACWI" is the index. In my visual, instead of seeing the Total of "9.28" in the thrid column, I want to see the difference of "0.09"..

Also, how can I force the visual to always show "ADRREP01" column before the "ACWI" column? It seems like the visual is just going by alphabetical order from the table..

Thanks!