3G/4G and a metal building

Gents,

I am interested in mobile broadband for my laptop but will be using it inside a metal building. As far as my cell phone goes I get 5 bars outside the structure and zero bars in. I'm guessing that the same will happen with a 3G or 4G USB stick. My thought is to put an antenna on the roof and run a cable inside to a repeater and antenna where I need/want the signal. I find that this type of setup is available for cell phones operating in the 850 and 1900 MHz range but haven't found anything that will work for me in the 3 & 4 GHz arena.

It would be appreciated if someone could point me in the right direction.

Thanks.