To save you the pain that I had recently, of trying to hook up simple support for the MCE remote control in your app, here is the important info that I found incredibly hard to locate via MSDN search:
A C# article called "Using Alternate Input Devices in Your Smart Client Applications" (easily translatable into C++)
A critical list of magic numbers, the most important of which are 0xffbc and 0x88 (the usage page and the usage id for the MCE remote). I'm not making this up.
The RegisterRawInputDevices API, into which you feed the above magic numbers in the way described in the C# article. You'll note the API docs give no clue whatsoever as to the magic numbers you need.
Please note I know very little about this, I am not claiming to be a domain expert here. However, if you are going crazy trying to figure this out, as I was, I hope this is useful.