Tina, to my knowledge, you can't add html code to a Facebook post. The badge is html code that you insert into an html reader/editor, and then it displays the image already linked to the site.
But you can take the image (as a standalone image) and link it to the home page URL (for instance) or any other URL by making a custom tab that appears at the top of a Facebook business page. I use Pagemodo to make my custom tabs. The five tabs following my fan count tab (see image embedded and attached below) were made with Pagemodo and each has another whole page behind it.
You can also go about this process a little more simply (Pagemodo is pretty complicated to use and clunky) by following these steps: http://blog.hubspot.com/blog/t...-Business-Pages.aspx
I haven't tried the latter process yet or applied it to this site, but if you do, let me know how it goes. Attached is the Proud Member image so you can give it a try.
I'll also try later this week, as time permits, but no telling when that will happen! 
