adapting single wire to bipole for receiving?

Hi,
I'm very new to this so excuse me in I seem stupid! I work in a steel building and we get no reception. The owner only allows small (boom box) style radios. Mine has a single wire hanging out for an antenna. Is it possible to convert it to allow me to connect an outside antenna and if so, please explain how.

Any help is greatly appreciated!!!

thanx! rremle