Hi Purushotham,
you are trying to convert from 8 to 24 char but using same wa_zfi0200-wbs_element in input and output
CALL FUNCTION 'CONVERSION_EXIT_ABPSP_OUTPUT'
EXPORTING
input = wa_zfi0200-wbs_element
IMPORTING
output = wa_zfi0200-wbs_element.
change output reference field.
i tried like this i am getting
data : input type string,
output type string.
input = '00000111'.
CALL FUNCTION 'CONVERSION_EXIT_ABPSP_OUTPUT'
EXPORTING
input = input
IMPORTING
OUTPUT = output.
WRITE : / output.