Maybe some info here :
viewtopic.php?f=3&t=40326
viewtopic.php?f=3&t=41760
the answer seems fine
set FWDIR=c:\fwh
set fwh=c:\fwh
call c:\fwh\samples\buildh.bat HB_FUNC
Compiling '.\HB_FUNC.PRG'...
c:\harbour\include\hbdefs.h(50) Error F0029 Can't open #include file 'stdarg.h'