this is one of the WantedFeatures
environment variables could optionally be read in addition to command line parameters.
For example the environment variable INCLUDE could be set instead of using an --include directive.
JohannesBerg: I don't see the reason for this, what advantage does it have over the command line?
Especially in the case of –include it saves the trouble of specifying a potentially long (think "c:\program files\delphi 7\projects\common\include") include path every single time you call PasDoc. Of course this could be done by specifying –include %INCLUDE% if the environment variable has been defined. Hm, ok, reduce priority. 
– ThomasMueller
JohannesBerg: write a ba{tch|sh} script