You shoud use the DSE and quick surface reconstruction workbenches to create lines, 3d splines sections and surfaces out of the pointclouds, and then use those surfaces to replace faces of the solid were needed. TO import the point cloud you should do it from the DSE workbench as a ASCII file or txt or igs... using the import tool.
In the DSE workbench you can clean and work the clouds, and the QSR will help you creating geometry from the cloud.
also when you have the cloud properly cleaned, you can fit geometry to it using the fit to geometry tool from the freestyle workbench.
Hope it helps