The reference to an "outer glow" makes me suspect that Michaelab is wanting an aura surrounding the glowing ball. (Confirm/deny this, Michaelab?)    Poser is a skin/surface type renderer, not a volumetric renderer, so it's not trivial. 

You could try using the atmosphere feature;  it is touchy to adjust and you only see the effect at full render, not in preview.  I don't know if this method would work;  I haven't tried it.

You could try adding a somewhat larger sphere surrounding the glowing ball, and use a fairly transparent material -maybe a double edge-blend node?- with high ambient value for the outer "aura" sphere.

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