The @ or the + before the name of a user will be put automatically by executing the following command:

/msg L chanlev <yourchannel> <user> +ao/+av
(type this command without the < and the >)

-take +ao if you want the user to set as an operator if he joins your channel, take +av if you want him to have voice (+) if he joins the channel !
-When you executed this command the user has to rejoin your channel and then everything will run automatically!