Logging into chat with an OAuth token is well documented:
https://github.com/justintv/Twitch-API/blob/master/IRC.md
If you want to mod a user in multiple chats you would first have to generate an OAuth token for each account (see this is you want to create your own app or use my generator), store that and then connect to chat with each account and send a command to mod the user:
PRIVMSG #channel :.mod username