effect creation in audacity

how create new effec in audacity
through a script or class Effect ?

Nyquist

http://wiki.audacityteam.org/wiki/Nyquist_Plugins_Reference
http://wiki.audacityteam.org/wiki/Nyquist_Documentation
http://wiki.audacityteam.org/wiki/Nyquist_Basics:_The_Audacity_Nyquist_Prompt