RCA TV w/ built in DirecTV receiver

I have a RCA model F38310 HD TV with a build in DirecTV reciever. I want to add a DVR or TiVo type device. Can this be done in conjunction with the built in DirecTV reciever, or will I need to get a new reciever that can then be wired to the DVR and bypass the built in one???
Thanks,
Ted