I think there are a few questions to be asked :
Is this your model? Is this an original Lightwave model?
Usually in modeler you can put the model in the right view, select the points in the section you want and copy them to a new layer then simply select the points in order and hit the "p" key for polygon. This can be difficult if the model was imported into lightwave because it probably was tripled (the polys) or frozen which creates a dense geometry.
If it was your model you might be able to go back to an earlier saved version where it might be a simpler mesh
If not, there are tools in Lightwave that can simplify the mesh like band glue or Reduce polys and others. these tools help but it still takes a lot of work to get amanageable mesh out of it. Since you are just taking slices of the exterior it might work. hope this helps some
