'Transfer' wifi from upstairs room to 20m away?

A novelty question here;
We have a house in a German village and we want internet there.
Line rental plus BB would be about £500 a year, and we only spend around 2 months a year over there.
Luckily we have a possible solution - my wife persuaded the neighbours to let us use their wifi (we will pay them a contribution), but don't want any cable link. I don't want to disturb the old couple any further after they gave us their wifi password.
Our kids are very happy, but the wifi can only be 'seen' weakly from one upstairs bedroom. I want to pick it up, transfer it about 20m down to our living room and retransmit as stronger wifi.

A wifi repeater will just give us a stronger wifi in the upstairs room, because the house is very solidly built with concrete.
I looked at external wifi antennae, but they appear to pick up the signal and send it down a usb cable, for a max distance of 5-10m, and can only be plugged into a computer directly.

Something like a wifi booster with an Ethernet output, which can be taken elsewhere an plugged into an access point would do it - does anyone know if such a thing exists or works?

A Netgear Trek will do that

The Asus EA-N66 will pick up the wireless signal and give you Ethernet than means you can run a cable downstairs to a router or wireless access point of your own choice downstairs.

That looks very promising for £20 from Amazon - Thanks.

Right, I bought the Netgear Trek, and it does seem to do what I need. It will pick up wifi and either rebroadcast as a stronger signal (booster mode) or it will output via ethernet to create a wired connection. I got 20Mb through the route 38Mbs router -> powerline into mains -> powerline wifi plug -> netgear trek -> ethernet cable -> laptop which I thought was [censored] amazing!

What I am hoping I can get working in Germany is taking the newly wired signal 20m away deep into the house and hooking it up to an old modem which I have configured as a wireless access point.

I'll let you know if it all works out.

Good speed

I tested mine out capturing my neighbour's BT Openzone connection before I take it to the States to avoid the ridiculous hotel policy of limiting wifi access to one or two devices. The best thing about it is that it can access and hold onto connections you have to login to using a username and password in a browser.

Final update; I'm in Germany and I set everything up and....I think this is the most successful recommendation of a gadget ever.
The Trek sits upstairs, receives the neighbours' 40Mb down 10Mb up wifi and rebroadcasts it as a booster at half speed. It also provides an ethernet output which I take downstairs with a 20m flat ethernet cable and feed into an old O2 router I have configured as a bridge. I connect my desktop to this bridge, getting the full 40/10 speed, and the bridge also puts it out as wifi for the whole downstairs area. It's all pretty stable and is as if we had our own independent BB feed.

It is exactly what I wanted - thanks a million for the recommendation Batboy.

Excellent news

I trust you take your neighbour some decent English beer or the occasional bottle of Single Malt!

Cooking them a barbecue tonight and will pay them too.
They don't need beer from England - local Bitburger Pils is excellent.

Whenever I go across I take some Fullers Vintage Ale - even with good local beers available, it always goes down very well.