i can’t test but check others current existing action.config files like https://github.com/clockworkpi/Menu/blob/master/20_Retro%20Games/Pcsx%2B/action.config
assuming you extract drastic folder into /home/cpi/apps/emulators/ and got your roms into /home/cpi/games/ds/ a file like that may work :
/home/cpi/apps/Menu/20_Retro Games/drastic/action.config
ROM=/home/cpi/games/ds
ROM_SO=/home/cpi/apps/emulators/drastic/drastic
EXT=nds
LAUNCHER=
TITLE=ds roms
SO_URL=