`This one makes use of the fact that PMX includes the variables
`and their values when it writes a Geometry File.
`That means you have to do this maneuver before you read in your
`working Geometry File.
enter PMX /direct
STR programdir:=PROGDIR
WRITE variable.gf
CLEAR
QUIT
set error=-4
read variable.gf
clear
\Program folder is {gf.programdir}

`This one uses a regular text file to transmit the PROGDIR information.
`FOUT is an undocumented Part Maker secret. 
enter PMX /direct
FOUT (CREATE) temp.txt
FOUT (EVAL) PROGDIR
FOUT (CLOSE)
QUIT
variable (str) s
read (data) temp.txt
read s
read (data) off
erase temp.txt
\Program folder is {s}

`This one avoids using PMX, but like the first example above
`it reads a Geometry File.
read ^^fv.gf
variable (st) s="{GF}"
clear
variable i
set i=chars "{s}" minus 5
set s=left {i}, "{s}"
\Program folder is {s}