Hello,
Currently you are able to set the following page specific meta content:
Page title
Page description
Page keywords
Page tags
For adding another content I would suggest you to use a custom webpart which would dynamicaly generate the content (e.g. create a custom field for the menu item and display the content with a custom webpart) or you can parse the whole header text in the CMSPages/PortalTemplate.aspx.cs file in the OnPreRender method and add your custom tags.
Best regards,
Boris Pocatko