Dear Peo,
Thanks for the reply. When trying out your formula, I found it would skip
the first empty row and jump to the next one. Thus adding the hours of two
orders to the sum. This has something to do with the row() function that you
use.
Frustrated by not getting it done, and thinking in circles, I decided to
build the formula from scratch with the MS help file as reference. The end
result that works is the following matrix formula:
=SUM(AE9:INDEX(AE9:AE206;MATCH(TRUE;ISBLANK($B9:$B206);0)))
The thing that was most confusing was that the index() function returns the
CONTENTS of a cell when used on it's own, but it returns the ADRESS of a cell
when used inside another function such as SUM().
Thank you everyones help. Using the MATCH() and ISBLANK() functions in this
way is really a new insight.
Regards,
Andre