The only way I know for creating/using scenery macros is the "old-fashioned" method using the Airport or FSSC scenery design programs. These will import API macros created with EOD, VOD or FSDS. Older FS98 3rd party aircraft can be converted into API macros or standalone BGL files with M98toBGL. All these programs/utilities (with the exception of FSDS) are freeware & posted in the scenery design section.