Try...

=INDEX($C$1:$H$1,MATCH(10,INDEX($C$2:$G$4,MATCH("S ite
B",$A$2:$A$4,0),0),0))

OR

=INDEX($C$1:$H$1,MATCH(B9,INDEX($C$2:$G$4,MATCH(A9 ,$A$2:$A$4,0),0),0))

....where B9 contains the number of interest, and A9 contains the site of
interest. Adjust the ranges accordingly.

Hope this helps!

In article ,
"bankscl" wrote:

I have a spreadsheet like this:
Name Total week1 week2 week3 week4 week5 etc
Site A 5 5
Site B 10 10
Site C 12 12
(140 sites)
In order to feed my database I would like to have a formula that looks for
the week that contains the number from the "total" column and gives that week
as a result.
i.e. "Look for 10 in the Site B row and tell me what week it's under"
It seems like it should be so simple but I haven't been able to find a way
to make it work using Hlookup, vlookup, Index, or Match..
Any help is appreciated.