How would you create a search help exit to allow a field from a help view which domain is case sensitive so that this field can be searched non-case sensitive?
To the best of my knowledge, you can't. You would need to create another field on the table (APPEND structure), containing the non-case sensitive values. You would have to keep that field populated through user exits, and then use that for your search help.
This was first published in April 2002