Sending commands to a DOS app from Delphi ?

Is it possible to send commands from a Delphi app, to a DOS app ?
I understand how to create a .pif file to display a DOS window, but
this is not really suitable for what I have in mind. If at all
possible, I would like to input commands to a command-line based DOS
application, and receive the command-line output back. If this can be
done with a non-visible DOS window; even better !

Any comments appreciated, Thanks.

Simon R Bascom