Class of service

Hi, I just bought class of service, I was thinking that I can limit a DISA to external route but I was wrong, also I was thinking to limit a 5 extension to call the Director and I was wrong too, there is any way I can do this with Class of service. Also I can limit a Contact Group but I don’t have any and I’m able to see 2 I don’t know from where, this contact group is to work with the enpoint Manager and resphone apps?, the instruction are very limited and it’s commercial module
thank you