How to connect a USB keyboard to UR242

I want to use my Korg Microkey keyboard with the UR242 and an iPad. However, since the Microkey is USB-powered and has no MIDI I/O (other than the USB) there doesn’t seem to be any chance to make this work. Does anybody know of a USB-to-MIDI adapter that will supply power to the keyboard AND provide a connection to the UR242? Or is it possible to connect the UR242 to the Microkey via its USB hub and then connect the Microkey to the iPad? Somehow I doubt it…

Thanks!