This is a simple Python script for converting a 3D printing .stl file to a LDraw format .dat file. Then you can use the part just like any other part in your favorite LDraw viewer or CAD program.
Usage:
> python stlToDat.py input_file.stl output_file.dat
If the output file is not specified the input file name will be used with a .dat extension.
The STL file needs to be in millimeters.