How can i redirect to my ownpage before the 404.php page redirection?

I have a page in my site which is not created in my WP-admin pages,posts or category. when in entered the page name in url it redirects to 404.php page. Now my question is how can i execute that page without rediects to 404.php page?.

I need to control the redirection b开发者_开发技巧efore the 404.php redirection happens?. Is that possible?.please help.

I believe url rewriting allows all url's to redirect to one script and with that you can then redirect the user to the file they requested, and if the file the user requested does not exist, you can create your own page for 404.