Anyone has an easy approach on the below please? 
I want the output of my "ls" command to output only the 5th-9th characters only.
For example:
ls FILE*.txt
==>>
FILEXINOO123.txt
FILEBASHY007.txt
FILEPERLA456.txt
FILEAWKER003.txt
FILESMILE001.txt
I want the output of my "ls" command in a single like this:
XINOO,BASHY,PERLA,AWKER,SMILE
Thank you! 