Featured Image link

When I make a new post with a featured image attached to it, I can make the image clickable with a url of my choice.
I want my featured posts on my frontpage to link directly to the url I’ve attached to my image (of that featured post)…
Because right now people have got to click on the image, going to the post, and have to click again on that image to go to the site mentioned.
I saw the post from luvdov (http://wordpress.org/support/topic/featured-image-link) that explains this but, it is not working for me. I set up the custom field and when I click on the image it still takes me to the post displaying ID, $key, true); ?>

Any help is appreciated!