I want to copy a network signal that is already being broadcasted in my house and copy it on a router downstairs my server can have internet. I have DD-WRT installed on it as well. I would also like to be able to access my server managment tool on the repeated network. Thanks in advanced!
I believe what you're wanting to do is setup a Repeater Bridge. This will repeat your wireless signal (acting as a secondary access point), and will allow devices connected to the ethernet ports to access the main router. The DD-WRT Wiki has a pretty extensive article on setting up a Repeater Bridge.