How do I serve at USASMDC while in the National Guard?

While on deployment I had a discussion with the Brigade Commander at the time about his space badge. He said he did a stint at Colorado Springs as a national guard service member and infantry officer. He went on to say that each state sent a national guard representative to the command. I'm guessing an ADOS/AGR appointment. I've been searching for more information online for awhile but it all seems to be guided towards the active side of things unfortunately. He made it seem like it was MOS immaterial and had opportunities for enlisted as well as officers. If so is there a particular packet to fill out? Any relative information would be highly appreciated.