ER problem: find string in string

Hello List,

writing some ER for a report i have the following problem:
I need to find a string in another string.

Example:

i need to find 'cpg' in 'bkhbhjabdsf cpg jasbdhasd'

i even don't need the position, only if the string is included...

Looking in the KG i found nothing, BSFN B96701 is not working as expected.
Has anyone a idea how to do it?
Any help would be appreciated!

Thank you,
hharald