I don't know any generally available way to extract codes from an .mxd file. I have a couple ways I can extract individual codes from an .mxd file, but those depend on special hardware (the easy way I just did it) or lots of effort plus special knowledge.

I looked at the signals in that .mxd file. The protocol is NEC1, the device is 135.69

As described in other threads, you can use MakeHex to generate the full set of 256 signals.

The On command is function 29 and the off command is function 30.

In condensed Pronto Hex, those are:

900A 006D 0000 0001 8745 1DE2

900A 006D 0000 0001 8745 1EE1

Do you have any learned signals for your projector? Rather than guess a model to get discretes from by similar model number, you should look at models that have the same ordinary signals as your model.