This seems like a weirdly unnecessary way to not quite manage to duplicate what lemmy has been designed to do.
How do I make it just work with just my original account?
You go to the community list for your instance and do a search on the URL of the community you’re interested in. Then (assuming that your instance is federated with the other one) your instance will create its own mirror of the community, and you’re done.
Absolutely.
But that’s not what I’m talking about.
I’m talking about making the leap from recognizing that such a being could exist to believing that such a being does exist. That, to me, is so bizarrely irrational that I can’t even work out how it is that people apparently actually do it.