Changing cookies location

Hi, I'm a new user to this forum.
I use Firefox 3.5 Portable in a terminal server environment, and need to change the location of cookies (the cookies.sqlite-file) from %programfiles%\FirefoxPortable\Data\Profile to the users terminal profile location, ex. %appdata%\ff_cookies.

Can I modify the prefs.js or add a FireFox.ini or is it possible at all...?

Would be VERY grateful if anyone could help

Anne