Apply A Curve To A Column

I'd like to apply a curve to a column of student exam grades and have the curved grades displayed in the adjacent column. Here is how I'd like to curve:

I like to make a linear function out of two coordinate pairs.

First Pair (x1,y1) = (Highest Exam Grade, 99) = (H,99)

Second Pair (x2,y2) = (Class Exam Average, Desired Exam Average) =(C,D)

Slope = (99-D)/(H-C) = m

Linear Function = Y-y = m(X-x) = Y-99=m(X-H)

Each student grade would = "Y" i.e. Y=m(X-H)+99