In Poser Pro 2012 (I think that's version 10.) you can do it pretty easily by just turning up the Ambient channel really high. (Light Emitter has to be checked on the object, IIRC. Indirect Lighting has to be used, as well.) But, there are also much better ways using materials in the Ambient and other channels to get really neat effects.

A quick Google using "poser ambient light emitter glow" brought up these discussions/links:

http://www.daz3d.com/forums/viewthread/40008/#726316

http://kobaltkween.deviantart.com/journal/Poser-Material-Basics-418487917

I KNOW there was a discussion thread in this forum regarding the exact issue you're trying to tackle. A user wanted to construct a cave scene with a glowing torch that emitted convincing light and there was a lively discussion about it. I'm sure that thread has exactly the information you need.

And, here it is, after a long an exhaustive search! :)

Enjoy.

http://www.renderosity.com/mod/forumpro/?thread_id=2865909