Hello Roy,
I got your point, i used below user exit.
MWMTO002 - Enhancement
EXIT_SAPLL03T_002 - User Exit at End of TO Confirmation (in Update Task) - Function module.
in this function module include i wrote this code, but if you see in the Attributes tab of this FM it is showing normal function module only, but will execute in update task as per short description.
So as per your above suggestion in this case also submit will not work ??
Thanks in advance.