I have an existing Ubuntu 12.04 server, with all the packages that I need in /var/cache/apt/archives.

I have a fresh install of 12.04 at a customer site with (deliberately) no internet access.

How can I install all the packages I need (from the first machine's apt archive), without messing up apt on the second machine. (It may gain internet access later.) I have a USB drive.

Will installing with dpkg do the job? Would that mess up apt for future package installs? How would I get the order of installing 100+ packages correct?