path$ [,refNum% [,dirID&]]
This statement launches the application specified by path$, refNum% and dirID&, and puts it into the foreground, making it the active process. The program that launched the application does not quit, but is put into the background. See Appendix A: Specifying Files and Directories, to see how the path$, refNum% and dirID& parameters are interpreted.
Inside Macintosh: Processes