In your AdminCP open up your style and go to edit templates. Put the following text in there where you want it to display:
Code:
http://$_SERVER['SERVER_NAME']$_SERVER['REQUEST_URI']
That
should work. I would think it works. You know the word "echo" so it seems odd that you wouldn't have tried this already - but you didn't say you tried anything.
One thing you may need to be aware of is if you use mod_rewrite... Things make look a little funny.