Time Capsule help for a complete noob to MacBook

Hi everyone

This is been killing me for about 2 months. Currently living in an annex down the end of my girlfriends fathers garden. The wifi doesn't reach so I got a Time Capsule so I could use it as a router.

We've got a cable and it's run from the Time Capsule, down the garden, into the house and plugged into router in the house.

That's where I'm now stuck. I've messed about with it and now my Macbook AirPort won't even recognise my Time Capsule.

This really needs to be in moron terms as I'm clueless. I've spent all this money and can't get it to do what I wanted it to do.

Any help is appreciated, so thanks in advance.