Hello, I imagine that this problem has already been discussed.
I have 12 spreadsheets (one per month) with a few columns, I would like to create on the last sheet (13 °) a macro that generates a table with a column in the months in a row and the sum of column values ​​grouped in individual sheets.

Let me explain

spreadsheets 1....12
A 7
B 6
C 9
A 5
B 2
G 2
A 2

Output spreadsheet 13

Gen Feb Mar....Dic
A 14 ...
B 8 ...
C 9 ...
G 2 ...

Tot 33 ... ...

I hope I was clear

Thanks for your cooperation