COMMAND

Supported DOS versions:	All versions
How easy to use?	Easy
How safe to use?	Very safe
How common?	Fairly common
Internal or external command?	External

Starts another copy of the command processor, COMMAND.COM.

COMMAND [path] [device] [/c command_name] [/e:nnn] [/k command_name] [/p] [/msg]

path specifies the path where COMMAND.COM is stored
device specifies the device to which input and output is made, if you don't want to use the console.
/c runs command_name and then quits. This must be the last parameter (otherwise any other parameters are treated as parameters for command_name)
/e:nnn specifies the size of the environment in bytes (DOS 3.2+ only)
/k runs command_name and then displays the command prompt (like an AUTOEXEC.BAT file) (DOS 6+ only)
/p makes the command interpreter permanent and disables the EXIT command
/msg stores all messages in memory (you must use /p with this option)

It's useful to know the parameters for COMMAND.COM to configure it. They are similar to the method used in the SHELL statement in CONFIG.SYS