Custom Post Type only as an rss feed?

I am trying to setup a post type purley to create an rss feed.

the reason being i want to be able to provide a “news” feed specifically to be used by a plugin i am developing.

ive thought this through alot, so please no suggestions of a feedburner or a mailing lists.

what i want is a custom post type where i can create posts in the admin area as normal, but for these to not be available on the front end of the site (except for as an rss feed).

i know i could do this by excluding a category, or excluding the post type in my theme loops.

but i want this to be as portable as possible (by hopefully creating a plugin from it).

i have created plugins with custom post types before, but im unsure how to attempt this.

1. im not sure but is there a set of visibilty args for the register_post_type() function which will set this up as i need it?

2. or do i need to create a visible custom post type and then filter all the sites queries to exclude it using a hook?

3. is this not currently possible with the current setup of custom post types?

I may be over complicating this, maybe there is a way to remove support for adding the post type to the custom menu feature?