There are two questions, how to configure and how to connect.
The first part of your question is depends on the router make and model, if you please illustrate it, then it will be easy to answer it.
The second part of your question is how to connect, there are many ways a router can be connected with another router, and if you are a home user then the best way is to use a Ethernet cable to connect it, the other choice is to use 802.11g module or Wi-Fi, but it might cost you.
Finally the problem you are facing could be the distance limitation of the UTP cables. If you are using CAT5 cable then the maximum length is the 328 feet or 100 meters, try to find it out the distances of the router hanged outside of your house to the inner one.
If the distance is the case then use CAT6 cable which can be support a 220 meter segment.
If distance is not the case then the probability is that the port on your router might be loose or the cable connector not fitted.
I hope this will solve your issue, or don’t hesitate to contact me further for the issue.