[drive:]path Specifies the directory containing COMMAND.COM file.
device Specifies the device to use for command input and
output.
/E:nnnnn Sets the initial environment size to nnnnn bytes.
/P Makes the new command interpreter permanent (can't
exit).
/C string Carries out the command specified by string, and
then stops.
/MSG Specifies that all error messages be stored in memory.
You
need to specify /P with this switch.