Lighting a sphere

I have a scene with a few objects - and I’m using Ambient and Diffuse material propreties for each object - how would I obtain a kind of spot light effect - say I have a sphere which I want to use to light the whole scene or part of - what changes do I have to make to lighting

You could try using the spotlight parrameters for the light - look in the big red book.

I’ve tried that - More detail of implementation please