I know of two ways at the moment. They are more of a work-around, rather than a genuine DTC capability though. One way is what Gliptal's Cartridger does (basically generating lua files and placing them to appropriate folders in the DCS\Mods\aircraft\A-10C\... folder structure). The other way is to generate (different) lua files and place them to appropriate folders within the .miz file structure, exactly as you guys have done in your downloadable NTTR mission, as I have noticed. Plus export all the nav points into the mission file, so they are accessible via CDU.
The only proper way would be having an independent external DTC file (lua, xml or whatever) that you could load your DTC from. That is, AFAIK, not yet supported by the module though.