The goal is to prefix and suffix all occurrences of a substring (case-insensitive) in a source string. I basically need to figure out how to get from source_str to target_str.
source_str = 'You ARe probably familiaR with wildcard'
target_str = 'You [b]AR[/b]e probably famili[b]aR[/b] with wildc[b]ar[/b]d'
In this example, I am finding all occurrences of 'ar' (case insensitive) and replacing each occurrence by itself (i.e. AR, aR and ar respectively), with a prefix ([b])and suffix ([/b]).