I need to compare to columns to determine if a part number (distinct) is in both columns, then determine the variance in number of parts. In this example, I'd like to have Column D find it's distinct part number in Column B, then subtract the Qty found in Column E from the Qty found in Column C to determine the Variance (Column F).

```
A B C D E F
1 Part # QTY Part # QTY Variance
2 1234 8 4584 20 0
3 5678 10 1123 25 0
4 1123 25 9652 10 5
5 1245 10 1789 45 (5)
6 1356 5 9652 15 0
7 1789 40 1234 7 1
8 4584 20 1245 10 0
9 9652 15 1356 4 1
```