One more obstacle preventing me from creating scenarios & campaigns for the X-Worlds mod too, in fact.
"G"? Never heard of it... it's reasonable to assume, you'd get a regular "saved" game structure though in the usual root folder of c:\Documents...(whatever your OS and game configuration details here); otherwise, it would seem logical that such files should prompt for file_naming (when cheated for) and be located in the installed directory of TA's "Tools/Maps" -- but i doubt it, since the editors are self-contained external assets without any connections to gameplay runtime-execution.