Hello,


I am looking for a value associated with the first occurrence of a specific
set. I am thinking using LOOKUP function, but it returns to me the lastest
occurrence.


Example:


1 NA 3000
2 NA 3001
3 B17 3002
4 B17 3003
5 B17 3004
6 B17 3005
7 B17 3006
8 B17 3007
9 B20 3008
10 B20 3009
11 B20 3010

What I want is the number associated with the 1st occurrence of the set B17,
i.e. 3002. Please do not suggest to order my data in inverse order.

Thank you in advance.
Best regards,
--
Isabelle