No good way that I know of.
There used to be a product that claimed to be able to convert ASP pages to VB6 code, so then you would compile the VB6 code into a COM DLL. But I haven't seen it advertised or even mentioned in AT LEAST 5 years. I think it probably didn't do a very good job and people just stopped using it.
If you want the protection of hidden code (e.g., via DLLs) then it's past time you moved on to ASP.NET.