I sometimes need to link to pages outside of the WordPress criteria, but logically have the Page included in the WordPress Page hierarchy.
So - I've created a solution (that I'm sharing). It's actually a template, but it doesn't really fit in the "Themes" category as it's mindset is more "plugin" based.
Simply upload the template-redirect.php file to your themes directory, then to create a new page that invisibly redirects to any other page, you
- Create a new Page in your WordPress control panel
- Enter the URL (or local path) you want to redirect to, as the only page content
- Set the Page Template to "Page Redirect"
Simple as that.
More info and download here.