smtalk, I'm very confused by your response. Perhaps I misunderstand what midas needs.
Midas,
You write that you're running DirectAdmin but that you don't have DNS set up on the server. Is that correct?
If so then I presume you've been running DNS elsewhere until now.
It appears to me that what you want to do is start using DirectAdmin to host DNS for the sites on this server, on the same server. Is that correct?
If so then you need to install BIND, and how you do that depends on the OS Distribution you're using.
But before you do that you should save your zone files (which DA should have been creating all along; they should be in /var/named/, so be sure to back them up somewhere. Also save /etc/named.conf as well.
When you install the DNS server do not install any kind of chroot option.
After it's installed copy back both the configuration file and the zone files you saved, and restart BIND. How you do restart BIND depends on the OS running on your server.
Note that none of this will matter until/unless you either change an existing nameserver at your registrar to point to your server and/or you change the nameserver records at the registrars of all the domains to point to a nameserver you've set up (at your registrar) for your system.
Note that I've presumed a bit of knowledge on your part, and I've made a lot of assumptions, in answering your post. If I've made incorrect assumptions, then feel free to correct us here. If you're not sure of how to proceed you may want to hire somone to do the job for you.
Jeff