By router I'm going to assume you mean a DSL/Cable "router" that also has a built in firewall. As a normal router wouldn't cause you any troubles.

If all traffic to your computer at work just simply passes through the router/firewall then it most likely isn't the problem. However, if it only say passes port 80 traffic through to your computer ( as a good firewall would ), then you'll need to reconfigure your router/firewall to let through the port you are trying to use.

Hope this helps...