1) Use ed , and just quit&save.
2) Use GeekGadgets (ixemul.library needed) bin/touch command to create a file
3) Fastest way : from CLI type :
echo "" >ram:file.txt
to create a null file named file.txt located in Ram:
P.S. Just read your reply, you need to know what parameters contains the config file, so if there is none existant, let the game create one on the first run (what usually happens) and then modify it with a text editor.
