I don't recommend using formulas unless the contents of a column must automatically update in the future, after the script is finished.
You could iterate over the rows with For Each Row() function but it would be messier, I think. Instead, vectorize the problem.
You can use this pattern:
data 1 = data column 1 << Get As Matrix;
data 2 = data column 2 << Get As Matrix;
Current Data Table() << New Column( "name", Values( data 1 - data 2 ) );
Of course you would iterate over all possible pairs of columns.