If I understand you correctly, you now have a base Debian installed. You have a couple of CDS that were burned using a different computer and wish to install packages from these CDs. Assuming these are Debian CDs, just do the following on a command line to add the CDs to your apt.sources list.
Code:
$ su
(type your root password)
# apt-cdrom add
(follow the prompts)
You might have to rinse and repeat for each CD. It's been a while since I've used it.
Once the CDs are added, you can use the standard tools to install what you need. I'm a Gnome user myself, so I would do:
Code:
# apt-get install x-window-system gnome-desktop-environment
Hope that helps ya.