Yesterday I made some tool that was need to drop multiple files onto it. GUI_DragFile handle only single file, Edit though accept multiple files, was not suitable for me.
Fortunately, with GUIRegisterMsg this become pretty simple.
#include <GUIConstants.au3>
Global $WM_DROPFILES = 0x233
Global $gaDropFiles[1], $str = ""
### Koda GUI section start ###
$hGUI = GUICreate("Test", 400, 200, 219, 178, -1, BitOR($WS_EX_ACCEPTFILES, $WS_EX_TOPMOST))
$hList = GUICtrlCreateList("", 5, 5, 390