Never cache dynamic file

Hi,

Is there a way that I can force EasyEngine nGinx not to cache a dynamic WordPress file?

My login pages shouldn't be cached so that they can be dynamically updated look and feel based on cookies set.

I have tried setting PHP headers in the hope that nGinx would read these and not even cache the response.

Expires: Thu, 19 Nov 1981 08:52:00 GMT
Pragma: no-cache

Any way I can do this with PHP headers alone rather than nGinx configuration changes?