If you install it from a DVD, you can use apt-get to install packages which are available on this DVD.
Anyway, here is what you can do :
Download the dvd image : http://releases.ubuntu.com/12.10/
Became root : "sudo bash"
Mount it :
mount image.iso /cdrom -o loop
Find your package :
find /cdrom -name 'openssh*.deb'
Install it :
dpkg -i /cdrom/path-to/openssh-###.deb