If your laptop has an ethernet port (cat5), you should be able to plug it into your network at work, although the network admin may throw a fit. Network admins are very critical of their network, and anything anyone plugs into it without prior knowledge by them- you don't wanna go there- trust me.
If you need access to your work from home, I'm sure your company can setup what is called a VPN (Virtual Private Network) for you. You simply log into work, from home, through the VPN, which provides you a secure tunnel through the Internet to your workplace. You have to have high-speed Internet at home, but other than that, you should ask your company these questions, for security reasons.