OK, easy but not perfect solution: if you go to the downloads on the GalCiv page there is the 1.02/bonus pack standalone patch, download that, put it on a zip/CD, stick it in your laptop your laptop and update it that way.
If you really want to have the latest patch and assuming that SDC can actually validate a serial number without being online (what I'm guessing your limitation is), here's what you need(ed) to do:
Install SDC on your laptop and use the software registration feature - this may not work without an internet connection, and if not, I don't know what to do. But if it does...
Next time there's an update on SDC, don't just update your desktop copy automatically, but right-click the update and choose "download and archive".
It will put a zip of the latest SDC patch in the "Backup" directory of wherever you have SDC installed. To then patch either of your copies (you'll have to move the zip into the "backup" directory for SDC on your laptop) got to 'archive' entry in the File menu and select restore. Point the dialogue at the patch and you should be good.
Caveat: even if everything else here works, I'm not positive if the archive feature will download everything needed to go from 1.00 to 1.03054, or whether it just downloads what is needed to go from 1.03053 to 1.03054.
Maybe someone who does know can chime in to supplement these instructions.