I am creating a dark alley scene and would like to know how to light it.  My vision is to have the alley mostly dark and shadowy but i do need some accent lights set up. one of the lights i need is a wall mounted one with the light streaming down the wall and lighting a portion of the street beneath it. the classic bare light bulb spot light effect. how is this done in poser or do i have to export my models to another aplication and do it there. 
any advice would be helpful.