Any such thing as a Partial Redirect?

I currently have a notice and a link on that points to I also have a ton of pages in subdomains on that url that are not accessed from the main page but are linked to other places on the web.

I would like to turn into a redirect to automatically send people to, but when I selected that option it started redirecting from any subdomain.

Is there any way to have the main page redirect, but allow people to land on the subdomain pages still if they have direct links?