For SELECT, INSERT, UPDATE, and DELETE you're ASP has been using ADO to query the Access database.
If you want to call one of the modules within Access you'll need to actually create an instance of the Access application object.
It is a bad idea to do this on a busy web server because you'd end up with one instance of Access running every time the page is called. This will quickly eat up system memory. Also, unless you control the web server, it might be difficult to convice your IT guys to install MS Office on a the server.
Perhaps the worst thing about going this route is that MS Office programs have a tendency to not terminate properly when launched from ASP... so you may end up with 20 copys of Access running on your web server. Oh, and since they were started by ASP rather than the desktop logged in user, there will be no icons in the system tray to let you know it is running... so you have to use the Task Manager to kill the orphaned instances.
The best thing would be to move the logic into ASP rather than a code module inside Access.