Finding Top N Values by Expression

[siddharthbanerjee1998]

I have a Straight Table in QlikView which has multiple dimensions and 3 expressions. The 3 Expressions are:

1. Sum(A)
2. Sum(B)
3. Sum(A)-Sum(B)

I want to to show Top 50 Records for Sum(A)-Sum(B). Could anyone recommend an efficient solution for implementing the same?

Thanks in Advance!