Project-specific template variables

I work on multiple project for various customers.
Various items in file headers (e.g., the copyright holder) must often be project-specific.

I have been using File Templates and would love to be able to automate this in my file templates.

So, the question: Is there any way to define project-specific File Template Variables?

Example Smarty File Template:

{{*
  * @package    ${PROJECT_NAME}
  *
  * @author     ${USER}
  *
  * @copyright  (C) ${COPYRIGHT_HOLDER}
  *
  *}}

In this example, the ${COPYRIGHT_HOLDER} variable would be replaced with the client for whom the project is being done.