Barring some sort of insane technological leap that rewrites the rules, offline playable characters will never be able to be moved to the online environment.
This is one of those features that would be awesome if it were possible. It’s not a matter of us figuring it out. It’s not going to happen. I very rarely will be so firm on an answer like this but it’s just not something we can do. You’d have to have some way to have the data protect itself and yet still be manipulated. Maintaining the integrity of that manipulation is not feasible.