This is only usable with a sepcial patched fw.img injected into a wii vc title, details on all the requirements may follow at some point.
The usage is quite simple, call WiiDRC_Init on boot and after that call WiiDRC_ScanPads every time you update your pad inputs.
See the "demo" folder for an example on how to use it in a bit more detail.
Both compiled Library and Demo can be grabbed from the Releases tab.