excel

[Kando2909]

=TEXTJOIN("",TRUE,MID(M43,SEQUENCE(,LEN(M43),LEN(M43),-1),1))

If you have this formula for cell in one column. Can you add this column to get a total? If so how?

[#2]

Post sample data and then show your desired output. Attach a sample file.

[#3]

@Kando2909 

It is possible but not trivial!

= SUM(
      MAP(target, 
          LAMBDA(x, 
            --CONCAT(MID(x,SEQUENCE(,LEN(x),LEN(x),-1),1))
          )
      )
  )

Naming the Lambda function helps both to shorten the formula and convey its intent.