I don't think anyone will think that you're impersonating Doxxy.
D0xxy or Doxy or Doxxu would be more like it.
At least I have seen worse than that, like Shlimby and Shlimmy. And they weren't banned for impersonating.
Confusion might happen but I don't think anyone will think you're intentionally trying to impersonate Doxxy with that name.