>How can I add and set norepro (all the same) for several users in
>one step ?
 
If NOREPRO is not your list's default
i.e., not * DEFAULT-OPTIONS= NOREPRO
 
then you would need to issue two commands
for each user that you were to add:
 
ADD listname userid@node firstname lastname
QUIET SET listname NOREPRO FOR userid@node