Adding server with Weechat:
/server add [1] [2]/[3] -username=[4]/[5] -password=[6] -autoconnect
/connect [1]
/save
[1] - Whatever you want the server to be called in the buffer list.[2] - The address of your ZNC install.[3] - The port of your ZNC install.[4] - Your username on ZNC.[5] - What the server is called in ZNC.[6] - Your user's ZNC password.