The short and easy answer would be no. However, there are other ways to regulate.
The problem:
Moving a consciousness out of a biological "grown" environment into an artificial/digital one presents your problem. Since a digital environment has been man-made, it can be replicated. And since it can be replicated, it can be copied. If there was a sure fire way to restrict illegal copying of any kind of data, it would already be widely used by every digital content platform. Without any handwavium, undiscovered futuristic tech, or magic-type restrictions (for example there's only one "soul" that's attached to a copy) there can be no hard restriction.
Legal restrictions:
How this was "solved" in the TV series Altered Carbon was by making it highly illegal to have multiple copies to exist at once, at high penalties or even death. How the solution would work (not necessarily true to this series), is by having large government controlled facilities monitoring the copies. This would be either by directly controlling the manufacturing of the copies, or by a world wide internet-like web constantly monitoring the status of any copies currently active.
Restrictions on manufacturing:
Another way to restrict multiple copies is to have a legal or moral requirement for the digital copy to be destroyed after it is downloaded into an artificial body. This could be government controlled as above, or could run on an honour system with the companies who create the copies.
More arbitrary restrictions:
Money:
Other restrictions you could put on the process would be time and money for example. It could be extremely costly to create and/or maintain a digital copy of a person, let alone multiple. Regardless of the positive effects this might have, it might still be too costly in the long run.
Time:
It could also take multiple years or even decades to create a single artificial human. Therefore you should be really sure that you want to create this person. It could also be that the new copies burn out very quickly and have a short lifespan. This would not only restrict the work they could do in that short time, but it would also make anyone who creates a copy think twice on whether it's worth the effort.
Effectivity:
The last thing I would consider is a more moral one. How effective would it be to have multiple copies of the same person? Would that at all work in the grand scheme of things?
Armies:
In the film series Star Wars there are multi-million personnel armies made of the same clone. However if we swap this for a digital clone or android, we would run into some very interesting problems. As you might know the storm troopers from Star Wars have been meme'd to death for being terrible shots. This isn't entirely canonical but does display a glaring problem: as soon as multiple super-soldiers would be created, someone would find their weaknesses and flaws and use it to effectively take down large swathes of these soldiers.
Dictators:
Your worry "hundreds of Hitler, Stalin, Mengele, Pol Pot and so on would send chills down the spine of almost everybody." is very true, it would definitely send chills down everybody's spines. However realise that most of these dictators were a product of their time and position. They got to where they were by using and abusing the troubles of their time and manipulate large amounts of people. But could they efficiently produce that position of power again? Would they be able to once again get the people behind them in a similar manner, when the people have already gotten wise to them and their methods have already been committed to history? Apart from a cult-like following, it would very well be possible that the general populace won't let them get away with that kind of thing again. Especially not if there were two of the same person, people with that kind of disposition would sooner take each other out as soon as possible rather than help each other.
Artists:
A similar thing would be true for the artists you listed. They were artistic revolutionaries of their time, and gained their popularity by charming a lot of people right then. But are they still at their height of popularity now? Would they be again? I would predict a large amount of people would label their "new" works as not "true" works. After initial hype they would not live up to the already existing catalogue. For the same reason certain bands aren't "the biggest rock band in the world" anymore despite still being around today in the same capacity.
Everyone and their ideas have an expiry date, and the human body is not necessarily the only the only limiting factor for this.