If you put your site in /var/www/html, and your CGIs in /var/www/cgi (note, NOT in /var/www/html/cgi) that should work.
However, lots of things may not work, because DA is set up as a hosting server, and many things, including PHP, etc., may not be setup to work in that directory; I'm just not sure. You'd have to thoroughly read the main httpd.conf file to see how http is set up for the main apache website.
Then you'd simply create an A record pointing to that IP#, and it should work.
If your IP# changes often enough for you to need dynamic DNS you're in trouble, since DirectAdmin won't work if your IP# changes, and DirectAdmin is sold for static IP. DA staff have made it clear here and elsewhere that they won't change licenses continually for systems hosted on dynamic IP#s.
Jeff