Sorry Kees, it was me who brought in the GA. I thought you were asking about a third party web counter of some type.
Are you asking about the statistics in the Reports section for Products Viewed and Banner Statictics? If so, I haven't found where one can set an IP block. Another user or Admins will have to answer that.
I would suggest when you post a question, the more details you can give the easier it is for someone to actually answer what you are asking.
Lee