Match Problem
 

Hi!
I have a table with some kind of calendar, in wich i have the vacations one
person that a mark as M(marked) and F(Vacancies). In other sheet i want to
know when are the vacancies near with a warning.
I thought to use if and Match formula, but i have the problem of letters
among the numbers. So How can i do? i.e.
Jan - 1 2 3 4 5 6 7 8 F F F F F F 15 16 17 18 ... 2007
Feb - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17... 2007
Mar - ....
Apr - ....
May - 1 2 3 4 M M M M 9 10 11 12 13... 2007

I need the M and F to know the days that were taked off and the days that
are marked, and it works fine, but the letters dificults me. Is there
solution?
I Count with your precious and wise advices. Thanks