Get and build lsof. Start your httpd normally (eg. not rooted), and do lsof -p <pid of httpd> to get a listing of all open files httpd needs.
Rereate this set of files, devices and all that is needed by httpd (eg. the lsof output) in the /chroot/httpd directory. Once you have done this, try to start httpd. If you copied all the needed files in place, httpd should be running (if you're that lucky...). Probaby there will be some paths in your configfile pointing to the wrong position, but that's easily fixed.
After that, youre done....