Hi,
try googling for HC16 compiler. I think Metrowerks Codewarrior V2.0 supported it, both Metrowerks and this Codewarrior seem being not available. Imagecraft or Cosmic may have something, but I doubt any of them will work on Windows 10 and perhaps as well on Windows 7. GCC toolchain for HC16 could be a way to go, but most likely it won't be as good as GCC for ARM.