Thanks ferdinand
I will treasure your help. Thank you very much!

Happy Monday, developer friends!
I would need a way to reverse the GetSplinePoint command,

I would like, given the position of a null object, to know its value as a percentage on the spline.

I accept advice and suggestions.
Thank you

Now Work
Thanks Andreas

Hi!
sorry for my bad english
I found this strange behavior in the Extrude tool:

import c4d
from c4d import gui, utils
def main():
	#Estrusioni
	settings = c4d.BaseContainer()
	settings[c4d.MDATA_EXTRUDE_OFFSET] = 20
	settings[c4d.MDATA_EXTRUDE_CREATECAPS] = False
	settings[c4d.MDATA_EXTRUDE_SUBDIVISION] = 0
	settings[c4d.MDATA_EXTRUDE_PRESERVEGROUPS]=True
	utils.SendModelingCommand(command = c4d.ID_MODELING_EXTRUDE_TOOL,list = [op], mode = c4d.MODELINGCOMMANDMODE_POLYGONSELECTION, bc = settings,doc = doc, flags=c4d.MODELINGCOMMANDFLAGS_CREATEUNDO)
	c4d.EventAdd()
if __name__=='__main__':
    main()

[c4d.MDATA_EXTRUDE_PRESERVEGROUPS]=True is always False