mga bro, im not so familiar with networking since i am more into a plug n play type of tech guy

hinoon its only for my own use.
anyways, i have a myDSL connection in my office with a DLink Wireless Router, however I want to connect a physical line to house which is about 200-300 meters away. this way i dont need to subscribe to another package. and also i can work while at the comfort of my own home.
question, what's the maximum distance for my lan cable(RJ45?) without using another hardware
if there is really a need for an additional hardware to be able to reach great distance what would that hardware be? i am currently in HK now and I think I can buy this things cheap.
thanks for the help!