get direction degree using GPS/GPRS SIM908?

Hi all,

I use this command: to inform about GPS location and the result will be as this:
<mode>,<longitude>,<latitude>,<altitude>,<UTC time>,<TTFF>,<num>,<speed>,<course>

I'd like to get direction of the point to draw an arrow the determine the direction, it is something like compass. how can I compute it?

I don't whither my question is clear or not, i hope it is clear ???

Thanks.