sshd issue

[trlists at clayst.com]

I have a few sites hosted on a virtual server with a commercial hosting 
company.  I have root access to the virtual server and can control my 
own configuration for pretty much everything.

I want some users to have a "jailed root" for FTP connections so that I 
can give an FTP login to someone managing site A and prevent them from 
seeing site B's files.

I managed to do this easily for straight FTP logins by adding some 
VirtualHost directives to proftpd.conf.  However users can also access 
the system via SFTP/SSH which I presume must go through sshd (the site 
uses OpenSSH).  I can't find anything in the sshd config file docs that 
lets me control the ftp logins specifically, or that lets me set the 
home directory for a specific user coming in via SSH and prevent them 
from going anywhere above that in the tree.  Anyone know if such a 
thing exists?  Another approach with the same effect?

Thanks,

--
Tom