You can map any buttons to any function in any driver. Is the Apple IR remote control identified as a gamepad device under Linux or something else? If it is something else, then you need to write a driver for it just like the joystick driver. The 2nd step is to map functionalities you require to which driver you wish, again, in the same principle as the joystick integration.
Just reading up, LIRC is good - I've just installed it on my intel ubuntu VM then switched the Apple IR sensor on the MBP to the VM. It knows the Mac Mini remote too.
So a modified joystick driver (IRRemoteDriver perhaps) could then use LIRC via a /var/run/lirc/lircd input file.
Question is - would it be better to upgrade the joystick driver or create a new driver completely based on the joystick driver. Any guidance that kstars could use quickly and efficiently would be good.