You’ll need to use either software or hardware. Neither are inexpensive. The best solution is at http://www.mpitech.com/ . Now, I have heard some people say they are somehow able to setup print queues that print through the AS/400 which I have never quite understood so I can’t elaborate further. You can ask a AS/400 savvy person that question ok.
Follow this URL for information on how to configure a remote OutQ for the printer. It covers all ASCII printers :