Will your DirecTV remote work with the TV? If so it may have a way to change the input. For example, mine uses the Enter key as the Input button on my TV when I hold it down. They usually have a switch so you can switch between a TV, dvd player, or other devices so if you currently have what you referred to as your "DirecTV box" set up as TV, you could set AV1 or AV2 up to control the new TV. Whether this will work on your equipment will probably depend on the model of remote you got with your system. There is a list of controls and instructions here to set it up: http://www.directv.com/DTVAPP/content/remote_codes2 If your current remote is not capable of this, you may be able to call them and talk someone into sending you a better remote that will do what you need.
