I emailed NEC technical support, and they say that they don't have any IR code files to download for their units. Maybe it's possible to buy a replacement remote control itself. I've tried a couple of online sites that I've found but they didn't have the correct remote for the device. I understand that other NEC remotes, in this case, may work for this particular device, but how can you tell? Thanks.

Here are some replacement remotes sites that didn't have the correct NEC remote.
http://www.replacementremotes.com/
http://www.newremotecontrol.com/
[Link: remotes.com]