=SUMPRODUCT(--(A1:A100="apple"),--(B1:B100="granny smith"),C1:C100)
See http://www.xldynamic.com/source/xld.SUMPRODUCT.html
explains the "--": http://mcgimpsey.com/excel/formulae/doubleneg.html
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"JW in Dubai" <JW in wrote in message
...
Who can help me with my issue?

I would like to summarize all fields in the coumn C that apply to given
'text' values in colums A AND B.

I tried VLOOKUP, but this is only applicable to the first value and
limited
to two columns

SUMIF is more flexible but I cannot find the formula to first select the
row
where both values in column A and B apply and only than the value in the
third column of the same row is added to the values in the next row with
the
same match.