If and Lookup

Hello I'm new on here today. Sorry if this has been covered elsewhere too.

I have a spreadsheet where I want to, I think, use the IF and Vlookup function.

I have 5 different grades of pay A to E. If I enter any one of these grades in a specific cell I need a formula to read the grade then lookup the appropriate column in a table for that grade. Column A gives the Performance as a percentage 1-120 then column B, C, D, E, and F have the Grade A to E. Hence if I type A as the Grade I want the lookup to give the answer in column B of the table and so forth.

I need E40 to look at G2 and lookup the value in the table for G40 (the percentage)