You first have to convert the stl scanned data to nurb surfaces from polymesh. Pro/E 2001 (and I think Wildfire) will only work with nurb surfacing, you can bring in a stl file in proe but you can't add to or do anything to the geometry.
To convert the mesh data to nurb data is easy to do but the problem is if the mesh is really tight the conversion will take a little time and the file size will be huge. Each one of those little facets will be a nurb surface.
If you need it for manufacturing I suggest you export it at level 10 with shrinkwrap and then use the exported model in Pro/MFG. In this version of Pro/E you cannot directly manufacture an STL, but this is a nice way to do it.