You're on a wireless network (assuming a laptop), trying to access a printer on a completely different network (assuming a desktop), or
You're on a Wide Area Network, trying to access a printer separate Local Area Network
I'm going to assume the first one. It's a bit of a complicated process to get going. The easiest thing I could suggest is set up the machines for Remote Access (either built-in to OS or using a program such as VNC), use GMail to send files to yourself as attachments.
Let me know if this is along the lines of what you're trying to do. If so, and if you need help getting a remote setup going, I will gladly assist.
If I understand correctly you have a printer on 1 LAN and a laptop on another. Both are linked via the same WAN.
If this is the case the first step is to make sure you have access to the printer. Do so by pinging it.
Second step is to get if your network admin to allow the printer to network to IPs outside of its LAN(if the admin will allow it and the printer supports it). From there it can be installed as a standard LAN printer.