Index Formula

Dear Experts,

                  I need the logic/formula for the below:-

Consider , I have a String "Anupam is a Student" , I want to split it into the row-3 as shown each char/space in a cell as shown, (need the Formula_1) for this, and then to populate row-4( for Indexing each char from right)-Formula_2 and row-2( to populate Indexing of each char from Left)_Formula_3

Thanks in Advance,

Br,

Anupam