See a lot of people misunderstand "admin mods" and think that to be an admin you HAVE to use a mod. That's a misconception. All Q3A engine games use "rcon" (remote control) system. It's very easy to use, all done in the console (and you can do it via web panels and game launchers like ASE or Qtracker too). Look it up anywhere, but our Dedicated Server forum tells you all.
Now if DC Mod has some different stuff (like setting up "subadmins" with less abilities) that's something else and you'll need to jump through the hoops on their forum to figure that stuff out. But for the basic JA stuff, it's all rcon and it's in the archives of the DS forum, if you look. Read the stickies and dug up old threads and read. You'll find the main stuff you need pretty easily. But DC Mod isn't talked about much here (the only thing I ever heard about it was some years ago somebody bashing it as a "cheat filled" mod, so I don't know much about it).