It sounds like you want to rename these files and then explicitly delete these reports which implies you are not deleting the whole of the workspace between builds. By also having this TOSHARE folder inside the workspace you are implying there that you are not using the archive artifacts or publish HTML plugins to handle these reports and store them outside the workspace.

I would look into using the publishHtml plugin this would avoid the need to rename and move them and keep the workspace. It is also best practice to delete the workspace so that each build is fresh.