creo4 config.pro option documentation for: TRAIL_DIR 
trail_dir
<directory path>
Creates the trail file in the specified directory rather than in the startup directory.
value for the option relation_file_editor
.
The command specified will be executed as it is typed in the config.pro
file. If the command does not open a new window, you can start the editor in the system window used to start Creo Parametric
.