Kevin,

You need the value of the environment variable at compile time, right? The only way to handle it is to write a little "helper application" with SetupBuilder to retrieve the value and then push it back to the SetupBuilder compiler. For example, let your helper.exe retrieve the value of the environment variable and write it to an INI file. At compile time (from your script), execute the helper.exe (using #run... with "Wait" enabled) and after it load your compiler variable with the value (#get ini...). If you need help with this, just let me know.

Does this help?

Friedrich