I am trying to build an automated 'year to date' column in a financial
summary worksheet but don't want to have to update the formula each month (ie
in month 6, sum cells A to F, then in month 7 change the formula to sum cells
A to G). Is there a function (or group of functions) which will 'lookup' the
current month e.g july and add up the contents of the cells in columns from A
to G (Jan to July)? The following month when I input August in a given cell
the function I'm looking for will recognise this and automatically add cells
A to H (Jan to Aug).

Hope this makes sense. Thanks in anticipation.