Simply, I have an array 10 rows X 24 columns with column headers of the dates Jan-06 thru Dec-07 (as full dates). In the cells under these dates are just random numbers. I need to sum (by row) a select range of these cells based on a start date and X number of months out from that start date.

In a column next to the grid (Y) is the 'Start Date', e.g Jun-06, and in column Z is the number of months out I need to go, e.g. 6.

Col AA is where I would like to return, in this example, the values from F2:L2 (start date = Jun-06, and goes out 6 months from there to Dec-06).

Does this make sense? I'm fairly certain it involves some or all of the functions mentioned in the thread title, but my attempts so far have failed... Any and all help is greatly appreciated!