Copy headers with internal redirect

[Witold Filipczyk]

Hi,
There is
location ~ ^/blahblah/
{
	internal;
}

There is also Apache which set header X-Accel-Redirect.
For example X-Accel-Redirect: /blahblah/1
but also set other headers. How in nginx copy all these headers to the client?
Do you know such a module?
Or how to write something like this?