It's not built into JFBConnect as it is currently. We have the full Graph API in PHP and the Javascript libraries implemented within JFBConnect, however, which would make adding some features like this pretty easy.
I'm not sure exactly what you're asking for, in all honesty though. From what I can gather.. you have a Facebook page. You have many users who are admins for this page. You want your site users (who are admins on the FB page) to be able to post from your site to the Facebook page's wall.
Does that sound about right?
Posting To Facebook Fan Page Wall As Admin
