The following formula assumes that your months are in A1:K1. From what
I see you want to match a Feb date to March. Assuming your date is in
cell A4, then the following formula will give you the relative position
of the appropriate month in A1:K1:

=MATCH(DATE(YEAR(A4),MONTH(A4)+1,1),DATEVALUE("1 "&A1:K1&"
"&YEAR(A4)-2000),0)

This is an *array* formula, it must be entered with Shift+Ctrl+Enter.

For a value of 21feb06 in A4 this formula will give you the number 9,
which is the relative column number of mar in your range.

I don;t know what else you want to do but this might be a start.

HTH
Kostis Vezerides