You want to include your own error messages in the conversion log.
WRITE: 'Fehler bei der Umsetzung von Feld xxx'
(code after calling the menu function and filling the appropriate fields):
WA_ERRORTAB-ID = '/SAPDMC/LSMW'. WA_ERRORTAB-MSGNO = 012. WA_ERRORTAB-PAR1 = 'A'. WA_ERRORTAB-PAR2 = 'B'. WA_ERRORTAB-PAR3 = 'C'. WA_ERRORTAB-PAR4 = 'D' INSERT WA_ERRORTAB INTO TABLE G_ERROR_TAB.
An appropriate message is listed in the log.