Limit SubDomain user access

hi
i want to make a subdomain on my domain
and get a some one a user & pass that only access to that subdomain directory
the problem is i can't limit the Disk Usage and BandWidth usage of a subdomain
how can i do that
best regards

Create the subdomain as a new domain.

You may need to arrange that with your hosting company; hosting companies may limit the number of domains you can have for your account.

Jeff