What do you mean by 'permanent' operator? Joining an empty channel will result in operator status, and as long as you stay connected to the IRC network that operator status will remain.
If you use an IRC network that supports channel registration, then that has nothing to do with mIRC - speak to the #Help channel and see if they can help. Not all networks allow channel registration, so only your network's help channels can deal specifically with those issues. You might also want to take a look at the network's website.
Furthermore, you might try reading
this thread.
Regards,