I have the following data:

Client January February March (and so on until December)
A 1 1 1 1 1 1 1 1
B 1 1 1 1 1 1

Each time I visit a client, I enter a 1 in the corresponding cell. I want to
detail, in a separate range, how many times I visit a client in each month.

Trying to clarify a bit mo I want to have a list in a cell with the
clients, a list in another cell with the months, and when I choose for
example A, February, to obtain a 3.

Is this possible?

Thanks in advance,

Regards,
Emece.-