1. html  cannot be processed by asp  or ASP.net unless you adjust IIS settings. Normally:
a. any file with .asp extension is handled by ASP.DLL
b. any file with .aspx extension is handled by ASP.net worker process

So if you want your .htm or .html files to have ASP/ASP.net code  you must adjust IIS settings to process them.

2. It sounds like you are using .asp (or Classic ASP). If so:
http://www.learnasp.com/learn/security.asp
http://www.learnasp.com/learn/security2.asp
will do what you want provide you map ASP.DLL to handle html files


3 If your question involves ASP.net this is the place. Let us know and we can give you the ASP.net solution.
If it involves Classic ASP then join: