I have the following Excel table:

x = blank cells

A B C D E F G H
1 x x x x x x M R
2 x x x x x M R T
3 x x x x M R T S
4 x x x M R T S Y
5 x x M R T S Y N
6 x M R T S Y N Q
7 M R T S Y N Q W
8 x x x x M R T S

I want to have Excel see the blanks (if there is one) and place the M in
column A and any cells up to column H to be back filled with the existing
data. Please see what I want the above table to look like after macro:

A B C D E F G H
1 M R R R R R R R
2 M R T T T T T T
3 M R T S S S S S
4 M R T S Y Y Y Y
5 M R T S Y N N N
6 M R T S Y N Q Q
7 M R T S Y N Q W
8 M R T S S S S S