sorry that i didn´t write before, im triying to achieve a solid shadow with skylight and ligthtracer, and disperse this shadow into a plane. hope i clear the question.
Let's see if I understand. You are getting shadows now, but they are too soft and you want an object to cast a harder shadow, but varying the Light Tracer settings and the Skylight Settings do not give you the results your looking for?
Am I correct?
If so, what you can maybe try is adding an additionl spot light or omni light, with 'Shadows' enabled. You can use that to force a specific shadow from an object.
If you don't want that light to affect other objects, you can click the 'Exclude'/'Include' tab and exclude other objects you don't want to light.
You can also add an 'Advanced Lighting Override' material to your object that will allow you to adjust the effect of the light tracer on that object.
Does that help at all?
//I tried it but not quite getting the results I think your looking for.
I'll think about it some more and maybe someone else will comment.