Post Navigation in 1 Category Only

I have used the exclude box and entered all of my category ids so that only 1 category has the navigation. On the very first post there is a navigation to the previous post that is “not” in that category. I only want this plugin to work in 1 category. Is there an easier way to achieve this as adding a field to INCLUDE …. only the category id that you want it to appear in?

http://wordpress.org/plugins/genesis-post-navigation/