How do I script these handles??

[Chazrox]

I've been trying to script the length of my audiofile in my reverb plugin. Is there a simple way just to grab these handles via script instead of scripting the buffer and samples for this purpose? Seems like the job is already halfway done with the handles existing there. How can I script these controls? I dont need to do any extra processing other than changing the 'start' and 'end' points.