Searching strings. Can not make sift do what i need

tgd · August 1, 2011, 1:09pm

Hello there.
I am having a hard time on that task and no idea how to do it.
I hope the below picture can explain my problems.

What do i need to make that work?

bjoern · August 1, 2011, 1:38pm

have a look at the attached patch

tgd · August 1, 2011, 1:49pm

Sift and me, friends again :)
Thank you bjoern for your quick help.