No, it's not an 18 series core, so you can't use the C18 compiler. It's actually a 16 series (14 bit core), despite the model number, essentially a 12F675 with an in-built transmitter.
I most admit, I did look at these (as they looked really useful), but after studying the datasheet decided they were far too complicated to bother with, particularly the companion receiver device!. Presumably you would also have to submit the completed device for 'licence free' testing?.