As each type of file, support by Rhino for opening or importing, has a different set of options, it not possible to write a single, generic file open function and hope to support all formats. Thus, if you want to open or import a file from RhinoScript, then script either the -Open or the -Import command using Rhino.Command. To obtain the objects that were either created or modified by that command, use Rhino.LastCreatedObjects.
Instead of doing this: Call Rhino.Command("<command_script>") Do this: Call Rhino.Command("<command_script>", False) Check th
There are also a bunch of great tips and tricks here: