Alternate column summation

[KoRn]

Hi guys,

I want a formula that can sum alternate columns (starting from AK6 ending HN6) i.e =sum(AK6+AM6+AO6... HN6) thus excluding the ones in between. I also want to exclude the following cells (AW6, AY6, BC6, BE6, CI6, CK6, FY6, GA6, GS6, GU6, HK6, HM6) which will be caught up in the alternate cell summation. So far I've got got something like =SUMPRODUCT((MOD(COLUMN(AK6:HN6),2)*AK6:HN6))
I'm not very good at Excel, so any help would be appreciated.

Thanks

James

[martindwilson]

=SUMPRODUCT((MOD(COLUMN(AK6:HN6),2))*(AK6:HN6)) works

[KoRn]

I tried it, but it doesn't seem there just yet... I believe these cells (AW6, AY6, BC6, BE6, CI6, CK6, FY6, GA6, GS6, GU6, HK6, HM6) that I want excluded in the summation, are causing the problem. How can I write a formula that excludes these specific cells in the calculation? Thanks for your help

[martindwilson]

hn6 is not in every other column starting ak6,
but why not just subtract them

=SUMPRODUCT((MOD(COLUMN(AK6:HN6),2))*(AK6:HN6))-SUM(AW6, AY6, BC6, BE6, CI6, CK6, FY6, GA6, GS6, GU6, HK6)

[martindwilson]

whats in those cells?

[KoRn]

Integers.

The spreadsheet is in such away I can't remove them... I need the information as independent information, but don't wish for it to be in the row summation. Thanks

[KoRn]

Would that work? I'm on a laptop without Excel at the moment so I can't try it. Thanks for the help thus far

[Aladin Akyurek]

For robustness...

=SUMPRODUCT(--(MOD(COLUMN(AK6:HN6)-COLUMN(AK6),2),AK6:HN6)-
    SUM(AW6,AY6,BC6,BE6,CI6,CK6,FY6,GA6,GS6,GU6,HK6,HM6)

[dredwolf]

why not just:
=SUM(AK6,AM6,AO6,AQ6.....)
will be long, BUT,saves the overhead of the sumproduct ?

EDIT-
even better, for the first formula of the run, you just have to click the cells,
=SUM(first cell (then ',') second cell (then ',')...etc...)