the big guys upstairs

hi
ok… we have a couple of pc`s on the shop floor which the powers upstairs have restricted internet access. They were never abused so i cant see what the problem is. If we were to use a portable browser on a USB stick to keep the internet browsing off the pc`s (firefox portable) then is there a way to open up to the internet via the main pc`s upstairs.
Grateful for any assistance.