Suspends execution of a Basic program to run a DOS command or batch file.
 
SHELL [commandstring$]
 
    - commandstring$    The name of a DOS command or batch file.
 
    - Your program resumes when the DOS command or batch file completes.
    - If you omit the command string, SHELL invokes a DOS shell and displays
      the DOS prompt. Use the EXIT command to resume your program.
 
Example:
    SHELL "DIR"