P8/Pro2010 can do it, albeit limited.

P9/Pro2012 and P10/Pro2014 give you much more capability.

P11/P11Pro can do it in both Firefly and Superfly.

What version of Poser do you have?

Using the Prop's ambient only works well for things which cover a lot of the camera view, such as skydomes. For relatively small but intense sources, such as a fireplace, lamp, LED, or pixie, the IDL response is not proportional to the perceived brightness of the Prop, so you need to use an unseen emitter. Except in P11 Superfly, which can adjust lightcasting of the prop.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5