On 14 Aug, 16:25, Pete_UK wrote:
Martin,

take a look here for an in-depth explanation of SUMPRODUCT:

http://www.xldynamic.com/source/xld.SUMPRODUCT.html

Hope this helps.

Pete

Thanks Pete, good page. For some reason I'm still not having any
sucess in coercing Excel to treat the TRUE and FALSE arguments as 1
and 0 by using the asterisk operator rather then the comma. I just get
a #VALUE error. However, adding zero is working, although it's not as
neat, so I'm not too worried.