Optional. The root folder to use in the dialog box. The user cannot browse higher in the tree than this folder. If this value is not specified, the root folder used in the dialog box is the desktop. This value can be a string that specifies the path of the folder or one of the
ShellSpecialFolderConstants values. Note that the constant names found in
ShellSpecialFolderConstants are available in Microsoft Visual Basic, but not in Visual Basic Scripting Edition (VBScript) or Microsoft JScript. In those cases, the numeric values must be used in their place.