Well, in your PBO you must have a code similar to
PROCESSBEFOREOUTPUT.
MODULE single_fields_move_and_or_set_attr.
LOOPAT some_itab INTO some_structure
WITHCONTROL some_control
CURSOR some_control-current_line.
MODULE single_line_move_and_or_set_attr.
ENDLOOP.
Code your LOOP AT/MODIFY statements in the "single_line_move_and_or_set_attr" module ?
What problems have you encountered and how did you deal with them ?
Regards,
Raymond