Hello all

If I have a table of data with multiple columns each representing a
month, is there a quick way to create a linked table with subtotals by
quarter, or by year.

So for example
A1=Jan08, A2=Feb08, A3=Mar08, A4=Apr08, A5=May08, A6=Jun08

I would like to sum in another table
A1+A2+A3 ("Quarter1")then in the next cell A4+A5+A6 ("Quarter 2")

Obviously this is easy but when you are dealing with several years it
is fiddly. Is there a quick formula I can enter to instruct excel to
add 3 columns together starting from the next one along from the last
set of 3?

Equally, it would be good to be able to quickly and easily subtotal
the years from groups of 12 columns.