Ah, the DAC+ Pro. Another thing to put on the Christmas list...LOL
As far as the remote you have several options. The path of least resistance is to download the android app and use your smartphone. There are both Apple and Android apps out there that will allow you to control OpenELEC. I have that as a backup but mostly I use as Harmony remote to control all my devices. Something like this would work if all you want is to control that one machine. I also bought one of these back in the day and it works on my PI in my bedroom but they are no longer produced. Now they make a USB CEC device that will work but I have no experience with them.
So, as you can see if you go out and start searching there are many other options than the ones I have listed above. AKA - There are many ways to skin the cat on this one.