Question : Problem: Send wireless signal through metal roof

I have a client with two barns. One they use as a house and the other they have an apt in the upstairs part. The house one has an N router in it and puts out a very strong wireless signal. The problem is that the apt in the second barn has a metal roof on it and no windows in the side facing the house. They apt has a Cisco G repeater but it wont pick up the N signal inside the apt.
      My guess is that all the signal is bouncing off of the metal roof. The front of the apt is wood and a door with glass in it. I was thinking of maybe mounting a N repeater by the front door on the outside of the house so that the metal roof wouldlnt interfere with the signal and the computers inside the apt could  pick up a wireless signal from the repeater through either the wooden wall or the glass in the front door.
    Maybe i am way off base here so i would like some suggestions. The two buildings are about 50-75 yards apart. Both buildings share the same phone number so i cant install a second modem in the apt. I just need to get the wireless signal from the main house to the apt without having the metal roof stop it.   TY in advance for your input.

Answer : Problem: Send wireless signal through metal roof

I think the best and cheapest way is:

to put an AP even iside, but an AP that permits to attach an external antenna, so you can have the AP inside, and somehow you pass outside the cable and you put the external antenna wherever you want.

http://shop.ebay.com/items/?_nkw=wireless+antenna&_nd1=0&_trksid=p3286.m270.l1313&_odkw=wifi+external+antenna&_osacat=0

Here you have the antennas for sale...


http://cgi.ebay.com/NEW-Startech-Wireless-Antenna-Cable-NRPSMA1FM_W0QQitemZ120328857577QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item120328857577&_trksid=p3286.c0.m14&_trkparms=72%3A1234|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A0|293%3A1|294%3A50

and here you have an example of cable.

Of course the cable should be long enough to go outside of the metal roof. And check the connectors of the cable. They should mount on the AP or repeater.