Hello this is my first guide so I will try to make it as helpful as possible. I started playing smash through dolphin recently and I have a wiimote but I don't have a gamecube controller. The first game I played on Netplay though I was unable to use my wiimote. After doing a ton of research I found a resource called glovePIE (all download links are below) and I couldn't find a designated smash bros script so I made one (Link below). All you have to do is download the links run the script to emulate your input and make sure that wiimote 1 on dolphin is set to emulated wiimote with the following settings(profile not important):

Run the glovePIE script and then you can play on Netplay just fine with a wiimote

Wiimote glovePIE file: https://drive.google.com/file/d/0Bz-5S-WTpYRZUlJkek1SdTJpTHc/view?usp=sharing

GlovePIE download link: http://glovepie.en.softonic.com/