It looks like the redirect is doing exactly what you're telling it -- any string matching /manual/* should instead go to -- and display the URL for -- /local/mydb.nsf/*. You'd use a redirect when something gets moved and you need to get the user to the new place.
I think maybe you want /local/mydb.nsf/ to be the database "underneath" but have the displayed URL show /manual? We have less experience with these vs. redirects, but you could try changing this from a redirect to a substitution. The substitution displays a different URL in the browser bar from what the actual page is.