Wrong track entirely. A redirect will, by definition, result in a changed URL. You're telling the browser to make a new request; that's what "redirect" means.
What you can
do is rewrite so the content really lives in some entirely different place, such as
... but you wouldn't really gain anything by this. You'd have to rewrite the URL globally, so URL + content is still one package.
Another route is to put the entire page inside an iFrame. The ultimate source would still be visible to anyone who takes the trouble to look at the page html, but it wouldn't be visible in the URL.
Either way, stay away from non-alphanumerics. Your server doesn't much like them. A simple
will do just as well. (Ask your cat to walk across the keyboard, and use the result as your physical filename.)
Third route is to put the material inside a protected directory where users have to login by some means before they can see it.
Fourth route is to attach a <noindex> tag, so the content will never show up in search engines, if that's what you are worried about.
Fifth route is ... Well, I'm getting tired.
Really, I think it will work better if you start by explaining, in English, what the underlying situation is and what you want to do about it. Set aside the whole redirect/rewrite question for now.