how to programmatically set some custom zWave configuration settings

Some Z-Wave device indicates that you can set a configuration variable or setting to change the default behavior.
in UI you do it by clicking the ‘Add Configuration Setting’ button. Indicate which variable number to set, and what value to set it to. The value can be a ‘1 byte hex’, ‘1 byte dec’, ‘2 byte hex’, ‘2 byte dec’, ‘4 byte hex’ or ‘4 byte dec’. you put the setting you want in ‘Desired Value’ and save

I would like to do exactly the same in LUA code so that I can for instance change the color of my Fibaro wall plug ( settings #62 controls the color of the OFF state for instance … )

What would be the right code/api to use for that ?

Seems solved by http://forum.micasaverde.com/index.php?topic=23415.0
I need to try…