Hello Jörn,
In my experience, you have two options:
A) Search all possible install locations and find the location of the executable.
B) Set some type of permanent flag during installation that your script can refer to. This is usually a registry key, but you could also use a text file that installs to the user data or app data directory in the same location no matter where the user places the exe itself. System variables are also an option, but I don't see a good reason to use those unless you need to run your script remotely. Be aware that antivirus or user intervention can snaffle these methods if you're relying on them, so if something critical relies on your script succeeding you'll either want to let the user know in the documentation or through a prompt or check/recreate this flag within the exe itself, perhaps as part of the launch process (or both).
For B), you would want to do this as a post-install action (available as an option in the "Advanced" tab of the Application Builder Installer Properties window) and write the install location to the location/file/variable you've chosen.
Regards,
Tom L.
