the parent path as a number, string (eg: "1:2:1") or array (eg: [1,2,1])
item
the item to be added as a child.
Description:
Adds a child to the tree node specified. This function has unpredictable result if the Model property is not set to MODEL_TREEVIEW. The item can be a string/number, RImage or RComboBox(for views with one column) or an array for views containing more than one column. After calling this function, you can't set the {Sort} property.