The command help is stored in the file "3DGSCommands.db" .

Using A7oogle, I found this post by jcl:
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=334043

Its easy to use, just click "Open" to open your 3DGSCommands file and add your own entries. However, there seems to be no way to tell SED to use several .db files, so if you provide a db file to other users they would have to overwrite theirs..