This takes in a MAC adress of a Wiimote and returns the bluetooth pin number of the Wiimote.
This converter implements the steps described on wiibrew to get the bluetooth pin of a wiimote from its MAC address.
The resulting pin might contain non-printable characters. And when you try to enter those characters in the pin field, it might not allow you to enter them. In that case, you might need to use other methods to connect the wiimote to your computer. like a Mayflash's DoplhinBar, or Bluetooth-passthrough.
Generally speaking, Bluetooth-passthrough is a way better way to connect a wiimote to a computer for use with Dolphin. so if you just want to use wiimotes with Dolphin, I highly recommend following this guide: guide regardless of whether you have problems with non-printable characters or not.