The released version of RW Cursor Editor (2007.1) does not have the latest scripting features (they will be available in next version of course).
If you just want to work with images, you can try the RW Photos beta, which has almost everything mentioned in the documentation, or RW Icon Editor 2008.1 (but that is not freeware).
In current version of cursor editor, you can use the RasterImage global object to work with images pixel by pixel and a couple of other objects to interact with user and clipboard.