COMMAND [d:][pathname] [console] [/P] [/E:nn] [/C command]

COMMAND is an external command. It is the part of your operating system that
responds to the commands you enter on the keyboard. For information about the
COMMAND.COM program, see the NEW_TERMS COMMAND.COM topic. 

[d:][pathname] specifies the directory pathname of the COMMAND.COM to be used.
    If not specified, the one in the COMSPEC environment variable will be used.

[console] specifies the new console to be used until COMMAND.COM terminates. 
    This option doesn't work on some versions of DOS. (The CTTY topic explains 
    what a console is used for.)

/P retains this COMMAND.COM permanently in memory until the system is rebooted.
    Otherwise, when <command> terminates or an EXIT command is entered from the
    keyboard, COMMAND.COM terminates and changes made to the DOS environment 
    space will be lost. When /P is present, AUTOEXEC.BAT will be processed 
    before further commands are accepted from the keyboard.

/E specifies the size of the DOS environment space where SET variables are
    stored. For DOS 3.1, nn is the number of 16-character paragraphs to be
    allocated (maximum of 62 paragraphs, default of 10). For later levels of 
    DOS, it is the number of characters to allocate (minimum of 128, maximum 
    of 32767, default is 620). May not work with the COMMAND command on some
    versions of DOS; use the SHELL line in the CONFIG.SYS file instead.

/C causes <command> to be executed. If present, this option must be last.
    Everything after /C is treated as part of <command>. <command> can be
    a BATCH command.
