Hi Patrick,
For text search and non sensitivy you should use:
CONTAINS("WERKS",'xyz1') ( to catch a word in a phrase )
or
CONTAINS("WERKS",'%xyz1%') ( % to works like like and catch part of a word )
You don't need a text index to try this out, but for special options like fuzzy or performance it's required.
Regards, Fernando Da Rós