Environment variables as Velocity variables' values in file templates

IDEA has a great feature of generating code for certain typical fragments (e.g. Java class headers) by processing customizable Velocity templates (via Settings | Editor | File and Code Templates). These templates can contain some predefined variables and some of them can even accept values entered by the user from UI. However there is no way (seems) to insert an existent external value, for instance, a value of an environmental variable. It would be useful for including into templates some values specific for current developer's environment like build stage id, current version being developed, custom user name, etc.

Would it be possible to enhance the feature this way?