I've got a range of grades in cols D:M e.g B,C,A,D,F,B,C,A,A,E

and a lookup table named "Points"
A 6
B 5
C 4
D 3
E 2
F 1

In Col N I'm trying to create a formula which adds the points for each grade
in Cols D:M

Using the example above the answer would be 42 but I'm stuck on how to
create a formula to calculate it.

Any help would be much appreciated

Thanks a lot