Hi Lynda. There is a sculptris forum and someone might move your post there, but Ill answer your question to the best of my ability.
Sculptris does not have retopo tools to the best of my knowledge. Neither, sadly, does Zbrush Core, although if you were interested in getting an introductory, affordable, Zbrush fundamentals program to learn with, you might want to check that out.
Also, it depends on what you mean by retoplogy. Are you talking about automated, or manual (building the new topology by hand) retopology ? In the case of the former, Zbrush is really good at this. In the case of the latter though, even as a near 20 year Zbrush user and enthusiast, I would not recommend Zbrush for this specific purpose (although I would recommend it for so many other things). The manual retopo tools are dated and arcane, not having been updated for more than a decade.
For manual retopology, there are affordable dedicated programs for that. I don’t want to throw around specific recommendations for other commercial software on this board, but I will mention that one of my favorite movies is “Top Gun”. And there is always Blender–that has free retopo tools available, though that is a substantial program to learn .