This is the explanation of the COMMAND command. It is EXTERNAL.

This command will start another instance of the command 
interpreter COMMAND.COM.

Switches:
        /e:nnnnn  Specifies the environment size and must be in the 
                  range of 160 - 32768
        /p        only used when COMMAND is used with the shell.
        /c string specifies a command to be executed and then stop
                  the command interpreter.
        /msg      all messages will be stored in memory.
Example:
       To take an interpreter and run the batch file Test.bat and
       then return to the old interpreter you type this:
           command /c test.bat