The only way I have been able to get good reflections, in Poser 6, has been with a Sky Dome.

Then I was reading page 197 of the Poser 7 Reference Manual:

"Poser 7 offers two methods for applying Reflection to your scene.  The first is to use a Reflection map, which is a 2D texture applied to a virtual sphere that surrounds you Poser 7 workspace..."

That sounds a lot like a built in Sky Dome, to me, but then the manual does'nt say where to create, nor apply, a Reflection map?  I checked th index, but there is no reference to Reflection at all.