I have a data in the range A7:D10. I am trying to perform a conditional sum
in cell B2 based on Region. I know I can do a conditional sum by using:

=SUMPRODUCT(--(A7:A10=A2),B7:B10) or
=SUMPRODUCT({1;0;0;1},{10;11;12;13})

But I also want the data to be weighted based on the number of days relative
to the dates in B1:BE. So if I could do what I wanted the the values in B2
will be:

=SUMPRODUCT({1;0;0;1},{10;11;12;13},{58%, 100%,100%,67%})

Note that the percentages are calculated by takeing the the date in B1 and
subtracting it by the dates in C7:10. I want it to be able to say:
If < than 365 then Days/365, If 365 then 1 Otherwise 0. This will allow
me to apply a weighted variable to my conditional sum.

Any ideas how to do this. Do I have to incorporate a sumproduct and an
array (CNTL-ALT-ENTER) formula?

Thanks

EM


A B C D
1 12/31/2006 12/31/2007 12/31/2008
2 Region 1 ?
3 Region 2
4
5
6 Amount Start Date
7 Region 1 10 6/3/2006
8 Region 2 11 12/31/2007
9 Region 2 12 7/31/2008
10Region 1 13 12/31/2008