Indexing text using first letter of the text

[umarhussain15]

I want to set the flashlight indexing so that it can tell elastic search to index text fields based on their first character. Currently elastic search is indexing the text based on default analyzer and on sort query it sort according to this.
I need in my case to change the analyzer. Is it possible with flashlight config file or do i have to manually change the analyzer?
If manually can anyone suggest a tutorial to do it.
Thank you.