I am trying to workout numerology in excel:

I have number 1-9 in row - 1
Alphabets A-I in row - 2
Alphabets J-R in row - 3
Alphabets S-Z in row - 4

I wish to know if I input a value from "A-Z" in different cells, I should
get corresponding numeric values say A20=S,B20=A,C20=I in three different
cells should return A21=1,B21=1,C21=9

Can somebody help me resolve this?

Thanks,