When you say "drawing" do you mean model? As in geometry? If so, the correct terminology is 3D object or 3D model. Drawing gets confusing, as the word "drawing" is used to describe a 2D image primarily.

If that's not what you meant, then you'll need to first learn to use a modeling program like Wings3D, Blender, Silo, Hexagon, Lightwave, XSI,3DSMax, or Maya.  You can use any of  these programs to model a 3D object using your 2D drawing as a reference.

If you meant something else entirely, perhaps posting an image of what you have that you wish to make usable in Poser would help clarify how best to answer your question.