Publishing a post by changing the status through the front end (php function) should publish the pos

When I create a post and publish it from the backend, things work as expected and the post publishes to my Facebook page. However, my system allows for users to enter drafts of facebook 'status suggestions' on the front and and then for an admin to come through and press a button to publish them which should then activate the 'autopost to facebook' for this post_type. However, this does not do anything.

I assume you are hooking the publish button on the backend instead of reacting to a post status change. Is there any hope of this working as I expected or could you suggest another way to go about building my system?

thanks