REVERSE

REVERSE(sCellContents)
Returns the contents of a cell with all the characters reversed.

REMARKS
If the argument is not a number or a text string, then #N/A is returned.
This uses the built-in VBA function STRREVERSE.
=REVERSE(REVERSE()) = ??
Public Function REVERSE( _

Public Function REVERSE( _ 
         ByVal sCellContents As String) _ 
         As String 

   If Application.WorksheetFunction.IsNonText(sCellContents) = True Then 
      REVERSE = VBA.CVErr(xlCVError.xlErrNA) 
   Else 
      REVERSE = VBA.StrReverse(sCellContents) 
   End If 
End Function 

For instructions on how to add this function to a workbook refer to the page under Inserting Functions