I know how relocation works, kawecki.

The DLL trick would work because Windows does all the relocation for you when you link to it, either at load time or dynamically with the LoadLibrary call.  The same as linking to any other DLL, except this one was just created.

If the operating system was designed to support it, it would even be possible to have the DLL "file" exist only in memory, and protected so that no other process would be allowed to access it.

And some hacker would find a way around it anyway.  (Or the more likely scenario, with a database of stolen keys would just create the keygen, rendering the rest of the protection scheme moot).