Dear Dor,
Thank you for your query.
This question was answered pro-actively by The Building Coder specifically for you nine years ago:
http://thebuildingcoder.typepad.com/blog/2009/08/library-paths.html
Please note that updated versions of The Building Coder samples including the CmdLibraryPaths code is available from the GitHub repository:
https://github.com/jeremytammik/the_building_coder_samples
I hope this helps.
Best regards,
Jeremy