SUCCESS in installing software in ubuntu on networkless computer using commands
 

i have ubuntu 8.04 with GNOME both at office (internet enabled) & at home (standalone so much that has no modem leave aside dial-up or broadband).

I install software at office using
#apt-get install softwarename
I copy all the debian files from /var/cache/apt/archives (from office computer) to /root/installed folder(on home computer)

Now I install dpkg-dev(on home computer) using ubuntu 8.04 cd

#dpkg -i libtimedate-perl_1.1600-9_all.deb
#dpkg -i patch_2.5.9-4_i386.deb
#dpkg -i dpkg-dev_1.14.16.6ubuntu4_all.deb
These files are present on cd.

i edit /etc/apt/sources.list (at home) to prefix # to all lines in it.
Then I append following to it
Run following command as root (at home)
Now I can install the softwares at home (which I have in office) via usual #apt-get install SoftwareName

The above steps are for first time only.
Now if I want to install more software at office (or upgrade) then before installing (or upgrading) them I do (in office)
#mv /var/cache/archives/*.deb /var/cache/apt/archives/*.old
This simply renames the debian files which I have already copied at /root/installed folder (at home).
Now (at office)
#apt-get install New-Software-Name OR click on 'get updates' button (for upgrade).

As you must have noticed & guessed.
Now i will copy *.deb files (from /var/cache/apt/archives of office) to /root/installed (of home).
Thus I will get only additional files downloaded during new-software-installation (or upgrading).
Just run at home (as root)
Some may say that apt offline is easier.
But I just wanted to learn while doing things.
Also I am putting less load on ubuntu servers :-)
Thank You

If you spot a mistake or get problem while attempting this.I am here ALWAYS.