I have a Samsung HL-R71xx DLP (can't remember those two numbers off the top of my head, but purchased in 2006), but there are one or two inputs that do not have discrete codes. My way around it was to just program a button to switch to a coded input and then add the command for the "next input" code repeated as needed. Just make sure you power on the device before you try to switch to it or it will skip over your intended input to the next input with an active signal. My set up is transparent so it just seems to switch to the input I'm interested in watching.

Programming the MX-3000 can make up for short comings of the equipment sometimes. :-)

L8r,
Don