SHELL - a statement that interfaces with DOS to exit the BASIC program,
        run a .COM, .EXE, or .BAT program, or a DOS command, and return
        to the program at the line following the SHELL statement
 
Syntax
  SHELL [commandstring]
    - If all arguments are omitted, DOS will give you a new COMMAND.COM
      shell and DOS commands can be entered at the DOS prompt
    - commandstring is a string expression that contains the name of a
      program to run and any program options