newbie question concerning user roles

hi folks. i would like to have my level 6 users (i call this role ‘boss’) to be able to create, delete and modify user accounts BUT only for users lower than ‘boss’ (and there is only one level below ‘boss’: it is called ‘student’). i do not want them to have access to other ‘boss’ or ‘admin’ accounts – i want to manage those myself.

using role manager, i have given ‘boss’ the ability to create, edit and delete users, but i don’t know how to restrict them to controlling only users below their heirarchical level. can anyone help, or point me to an article which would help. thanks! peter