Replacing configate types for relative paths

Question

Is there a way to use relative paths in replacement instead of absolute ones? I want to write this that does not work:

service { password = "qwerty" url = "http://example.com?user=John&password="${password} } 

Only works in this case:

 service { password = "qwerty" url = "http://example.com?user=John&password="${service.password} }