Ok, if you're correct, the diode apparently connects to Vdd of the chip if it's a PIC16F1823, which is certainly possible. If the diode blew, it means the PIC has drawn a very substantial amount of current - not good news. In your place I'd drop a 1n4148 in (with some agility you can usually solder one onto the pads of an smd diode) and see if thay revives your remote. If it doesn't, odds are one or more GPIO's of the PIC are fried.