icon_name is a standard character string (can be replaced by @)
associated with a icon file in a resource script.
handle is a value returned by a modified form of the API function LoadIcon.
Icons can include transparent regions where the background can be seen. They can
be of any size. Standard sizes are 16x16, 32x32, 48x48 and
64x64 pixels. Icons can be monochrome or use 16 or 256
icon_name can also take the form of an
integer handle surrounded by curly brackets or the name of an
external file surrounded by curly brackets.