The following command line switch supports passing symbol definitions into the compiler. Syntax:
/C:symbol=value
Example
COMPIL MYPROG/RC/C:APPVER=2/C:GUI="VISTA"
This specifies the /RC switch, plus two instances of /C to define two symbols, APPVER=2 and GUI="VISTA". These definitions are treated exactly as if the following had been inserted at the top of the MYPROG source code:
define APPVER=2
define GUI="VISTA"
Note the need for quotes when defining a string symbol (per the normal rules of the DEFINE statement).