Hello Deepa,
You can use enhancement EXIT_SAPLQPL1_006 to save the information in QALS table or Custom Table.
EXIT_SAPLQPL1_004 is used to bring the information on to the custom specific screen using the parameter I_QALS
EXIT_SAPLQPL1_006 is used to bring back or save the information from custom specific screen using the parameter E_QALS