Are you stuck on Excel or Google Sheets?

I need a formula (I think VLOOKUP) that will enable me to: Use data from one column, compare with another and tell me the difference. Im a teacher and want to work out the amount of marks needed to the next grade boundary. I've created the rest, but this has me stumped!

Please insert a formula into column D that brings the code from Column H into Column D, using VIN in column I as the look up factor. I think this is a vlookup function but I am struggling