Content “split” with search/replace

Custom Content Shortcode has a “split” feature to get different parts of a string based on the nth occurrence of a specified character. It would be nice to have the same option in Loops & Logic, but enhanced to:

Extract a substring, eg. [string, start, end]
Option to start selection from the start or end of the string, or nth character
Option to omit end of string (ie to the rest of the string)
Option to replace/concatonate substring with text
Regex option

I think there are some good examples in several programming languages to base this on, and make it as flexible as it can be in L&L.

I know this could be done in PHP, but not everyone is comfortable with it.