The below code will also help you in achieving your requirement, please find the Image below which shows the runtime performance,
DATA : charlength TYPE i,
final_length TYPE I,
lwa_charg TYPE mcha-charg,
lwa TYPE mcha-charg.
lwa_charg = 'ed12'.
charlength = strlen( lwa_charg ).
final_length = 10 - charlength.
lwa = lwa_charg.
DO final_length TIMES.
CONCATENATE '0' lwa INTO lwa.
ENDDO.
