ffmpeg bandpass filter

Hello.  We need to use ffmpeg to remove non-vocal frequencies from audio files in order to make the voices in the recordings easier to hear.  The instructions for ffmpeg give this explanation: http://www.ffmpeg.org/ffmpeg-all.html#toc-bandpass  Unfortunately most of that is Greek to me.  I think all we really need to do is reduce or remove all frequencies below, say, 200 Hz.  Does anyone know how to convert that requirement into the parameters on the above URL?  Thanks!