You can certainly set spotlights inside the lamp props and that'll light the wall with no problem. However, you'll need to add a little omni light here and there to support them -- without it, your scene will look unnecessarily high-contrast, given Poser's limited ability with ambient lighting. So place an omni near floor level in front of the bed (our POV). Set it for a deep blue and then turn it way down, to like 40% value. Set another to the right (also at floor level so it comes up to the model), make its colour a medium grey, and again turn the sucker way down. Finally, for a really gentle touch, put a spotlight over the table with the picture. Make it white, but set it for about 20% value, so the light just hits the photo and the top of the table.