Want to show the domain with full page url without shoing the forwarded domain

Want to show the domain with full page url without shoing the forwarded
domain

I'm forwarding a domain to another using IFRAME. so what ever the link is
it shows only the domain, not the path. Is it possible to show the path in
this case?? I only want to hide the domain on which the site is hosted and
want to show the domain which I'm forwarding.
ex: newdomain.com forwarding to olddomain.com now its showing
newdomain.com all time. But I want to show the path of the page after
newdomain.com in url