Using a .NET dll in a classic asp site

I wrote a website in classic ASP a few years back and I've finally got round to getting it hosted. My host supports custom dll files but charges a fee for registering them, however it says that any .net dll files can be linked to without registering as long as they are in the /bin directory of my site. I've rewritten the dll from vb6 to .net2005 and placed it in the /bin directory. The project and class in the dll use the same names as before so i've currently left the "Server.CreateObject("")" line the same as it was before, but this doesnt work. I have no idea how to progress from here but any help would be great, i really dont want to have to rewrite my asp site to asp.net as it around 100,000 lines of code. and id really like to avoid having to pay to register my vb6 dll