Daniel - good self support. Sorry for the delay, I've had family visiting for the last week. All the desktop VFX Forths have a file called VfxForthxx.ini in a directory related to the system. SHOWMACROS will tell you where it is, e.g.
INIDIR = /Users/sfp/Library/Application Support/VfxForth
INIFILE = /Users/sfp/Library/Application Support/VfxForth/VfxForth64.ini
for my Mac. There's a directory VfxForth in a system defined location, and an INI file inside it. The INI file is handled by the code in VFXBase/IniParser.fth and the iniparser shared library (see Tools directory).