ListViews in Windows aren't made to be editable. I bet that's why Patchou hasn't included it in the MP!L scripting, it's simply too much work with dirty workarounds. You can always create a separate window where you store each value in a editbox, so the user can edit it from there. I would have done that if I needed the items to be edited.
As said, it's not supported by the Win32, and I personally think it's not going to be added into MP!L. However what I would like to see is callback functions (so we can do stuff like this with subclassing). That would be even better!
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