One way:

=SUMPRODUCT(--(LEFT(A1:A100,2)="ES"),B1:B100)


In article ,
Bumblebee wrote:

I have a column of ISIN codes and next to it a colum of weights and I want to
add up the weights of only those ISIN codes that start with ES. Lets say one
ISIN code is ES098430202, another one is FR099878324, etc. How would I
construct the function?

Imagine

ES098430202 4%
FR099878324 6%
DE957632458 8%