Well, if it goes over your office, you can cut an access panel in the ceiling by the wall. Then you drill a smallish pilot hole to the outside, then make it bigger from the outside. Install one of these so you can get back to it later if needed.
Now you have your hole. To do the duct work, you can either use pvc or flexible dryer duct, just make sure any joints are sealed. Pvc would be easier, and better really. You can just push them in from the room your router is located and join them as you go. The hose would probably be cheaper, you’d just have to use a fish tape from the office side then pull the hose to your access panel.