you can have people sign up and not have them be regulars or vice versa, you could use a cookie instead to keep track of those people instead. Now I know that not everyone has cookies enabled, but for the most part they are negligable.
But if your website is not in PHP or ASP or some other scripting language you won't be able to keep track of them. You must use PHP, ASP, CFM, JSP, or some other dynamic language other than htm or html... check with your webhost to see if you are allowed to write scripts on your server, if not then this really won't be an option for you then. If your server is ASP (microsoft) then you will probably be usign a access database, in which case continue your post in the ASP forum