Can ProtectedSource show image instead of blank in WYSIWYG?

I have a plugin I created to insert custom PHP code. I've set ProtectedSource for PHP:

FCKConfig.ProtectedSource.Add( /<\?[\s\S]*?\?>/g ) ; 

Now, can the WYSIWYG mode show an icon to indicate there's code there, instead of being blank when in WYSIWYG mode? This would be similar to Dreamweaver which puts a little yellow "PHP" icon.

Thanks!