application to calculate sum of nth column in a csv file

I need an application that check csv files and finds the sum total of all values in any 2 or 3 columns I choose. So if i chose column 2 and 3 as an example, the app will calculate the sum of all values in column 2 and sum of values in column 3 and display the difference b/w both sums. this is an Easy and straightforward project . I need Fast freelancers