calculate the difference --vlookup not enough

I have one excel file, more than 200 lines, structure below:

column A B C D E F G
company department revenue company department revenue difference
0092 R010 1000 0190 R090 100
0190 R020 1100 0092 R001 300
0190 R030 2000 0092 R010 200

we have so many rows, we need to calculate column G, which is C-F but for same company and department, how to do?

in this case, row 1, column G should be 1000-200 (in row 3,column F)=800, for company 0092 and R010 (based on column A and B)

any idea to be fast

hi, you are wrong, it should be based on both department and company ID

your solution is based on department ID

but different company may have same department, for example in row1 0190 company may have department ID R010.

that's why I say vlookup not enough.

{=C2-OFFSET($F$1,MATCH(A2&B2,D2:D4&E2:E4,0),0)} is row 1 formula,

how about row 2 formula? it seems only working for first row

also, the formula only works search downward
given my row 3 is 190 R030 2000 92 R010 200

if my row 2 is 190 R020 1100 190 R030 30, the formula is not working, it can't get 2000-30 by search upwards. can you have a revised version? thanks

I'm using apple MAC machine, it doesn't work