Retrieves the index of the overlay icon in the system image list
#include <WinAPIShellEx.au3>
_WinAPI_ShellGetIconOverlayIndex ( $sIcon, $iIndex )
| $sIcon | The fully qualified path of the file that contains the icon. | 
| $iIndex | The index of the icon. To request a standard overlay icon, set the path to an empty string, and index to one of the following values. $IDO_SHGIOI_LINK $IDO_SHGIOI_SHARE $IDO_SHGIOI_SLOWFILE Windows 7 or later $IDO_SHGIOI_DEFAULT | 
| Success: | The index of the overlay icon. | 
| Failure: | (-1). | 
To use this function, you must call _WinAPI_FileIconInit() at application launch.
Search SHGetIconOverlayIndex in MSDN Library.