How to create a USB flash software repository?

Is there a tool that can create a software repository on a USB flash
drive, including all software currently installed on one machine, so
that I can use that repository to install the same software on a
non-networked machine?

I have my desktop PC running Linux well enough, but I also have a
laptop which hasn't been connected to any network for years. Running
Windows, this was a policy thing - the machine slows down too much
when running firewall, antivirus etc.

On Linux, performance is fine, but I have completely failed to get the
laptop to connect via my ethernet cable modem. This also fails in
Windows - something to do with failing to acquire an IP address. I
have also failed to get a WIFI network connection running between the
laptop and desktop PCs.

I have my doubts about whether the ethernet port is faulty, though I
don't think I ever got that PCMCIA WIFI card to work.

Anyway, this is 90% fine. The laptop has been doing non-internet
duties for several years, and that's all I want it to do. The only
trouble is getting software installed that isn't included on the
OpenSUSE install DVD.

With all the repositories currently available online, I'm guessing
there are tools that can manage these repositories, that may be able
to do what I want?