AW: deploying forrest with environment variables

>I'd like to deploy forrest as a webapp, and include the 
>environment as a parameter in the command line. This parameter 
>should be used to set some variable in the site.xml, depending 
>on the environment targeted.
>Any way to pass variable from Ant to site.xml?


>From the Ant point of view I would use property files for defaults and
-D parameters. 
But what does the Forrest script support?

Jan