I have a website at http://www.mydomain.com which has a corresponding facebook page at https://www.facebook.com/pages/mydomain/123456789.
I am looking for a way to integrate this facebook page URL into the open graph headers so that when someone shares my page, it actually shares the Facebook page instead of the site's URL.
Is this possible?
Perhaps you already figured this out as this is an old question, but since I stumbled upon it... If I understand your question correctly, you do not even need the ogp meta tags to accomplish what you want to do. All you need to do is go to http://developers.facebook.com/docs/reference/plugins/like/ and input your facebook page url in "url to like", https://www.facebook.com/pages/mydomain/123456789 from your example. Then select the options you want including the "send" button. Then get the code and paste it where you want it in your website. Now whenever someone clicks "like" on your website or clicks "send" to share your website, they will actually be liking or sending the url to your Facebook page and not your website. Is that what you were looking for?
You can now do this by setting the og:url meta tag to the url of your Facebook page. Keep in mind that if you do this, other networks that use Open Graph tags will probably share your Facebook page instead of the site's url, so make sure that's what you want.
<meta property="og:url" content="http://www.facebook.com/your-page"/>
