Как сэмулировать создание скриншота

#include <WinAPI.au3>

Global $nBytes
Global $file = @ScriptDir & '\color.bmp'

$X1 = 200
$X2 = 300
$Y1 = 400
$Y2 = 500; Coordinates of upper left and bottom right vertices of recatangle to scan

_Header($X1, $X2, $Y1, $Y2)
_BMPFiller($X1, $X2, $Y1, $Y2)

Func _BMPFiller($X1, $X2, $Y1, $Y2)
	$tBuffer = DllStructCreate("byte[" & 3 & "]")
	$hFile = _WinAPI_CreateFile($file, 3)
	_WinAPI_SetFilePointer($hFile, 0, 2)
	For $j = $Y2 to $Y1 Step -1
		For $i = $X1 to $X2
			$data = Binary(PixelGetColor($i, $j))
			DllStructSetData($tBuffer, 1, $data)
			_WinAPI_WriteFile($hFile, DllStructGetPtr($tBuffer), 3, $nBytes)
		Next
		If Mod($w, 4) > 0 Then
			$tmp_buf = DllStructCreate("byte[" & Mod($w, 4) & "]")
			$zero = Binary(0)
			DllStructSetData($tmp_buf, 1, $zero)
			_WinAPI_WriteFile($hFile, DllStructGetPtr($tmp_buf), Mod($w, 4), $nBytes)
		EndIf
	Next
EndFunc

Func _Header($X1, $X2, $Y1, $Y2)
	Global $w = $X2 - $X1 + 1
	Global $h = $Y2 - $Y1 + 1
	$hWrite = FileOpen($file, 16 + 2)
	FileWrite($hWrite, 'BM'); 2 bytes - 1-2
	$imsize = ($w * 3 + Mod($w, 4)) * $h
	$size = $imsize + 54
	FileWrite($hWrite, Dec(Hex($size)));      	4 bytes - 3-6
	FileWrite($hWrite, 0x0);                 	2x2 bytes - 7-10
	FileWrite($hWrite, 0x36);                	4 bytes - 11-14
	FileWrite($hWrite, 40);                 	4 bytes - 15-18
	FileWrite($hWrite, Int($w));           		4 bytes - 19-22
	FileWrite($hWrite, Int($h));             	4 bytes - 23-26
	FileWrite($hWrite, Int(1572865));        	2x2 bytes; 2bytes - 1, 2 bytes-24; 27-30
	FileWrite($hWrite, Int(0));              	4 bytes - 31-34
	FileWrite($hWrite, Dec(Hex($imsize)));   		4 bytes - 35-38
	FileWrite($hWrite, 3780);               	4 bytes - 39-42
	FileWrite($hWrite, 3780);               	4 bytes - 43-46
	FileWrite($hWrite, Int(0));              	#########; 4 bytes of zeros - 47-50
	FileWrite($hWrite, Int(0));              	#########; 4 bytes of zeros - 50-54
	FileClose($hWrite)
EndFunc

#include <WinAPI.au3>

$sFile = @DesktopDir & '\Screen.bmp'

$X1 = 0
$X2 = 500
$Y1 = 0
$Y2 = 500

$hWnd = WinGetHandle("[CLASS:Progman]")

_ScreenCaptureToBMP($sFile, $X1, $X2, $Y1, $Y2, $hWnd)

ShellExecute($sFile)

Func _ScreenCaptureToBMP($sFile, $X1, $X2, $Y1, $Y2, $hWnd=0)
	Local $hFile, $iMSize, $iSize, $iW, $iH
	Local $stBuffer, $pBuffer, $iMod, $stMod_Buffer, $pMod_Buffer, $sData, $nBytes
	Local $iOld_Opt = -1
	Local $hKernel_Dll, $tWritten, $pWritten
	
	$iW = $X2 - $X1 + 1
	$iH = $Y2 - $Y1 + 1
	
	#Region BMP Header part
	$hFile = FileOpen($sFile, 16 + 2)
	FileWrite($hFile, 'BM'); 2 bytes - 1-2
	$iMSize = ($iW * 3 + Mod($iW, 4)) * $iH
	$iSize = $iMSize + 54
	FileWrite($hFile, Dec(Hex($iSize)));       4 bytes - 3-6
	FileWrite($hFile, 0x0);                    2x2 bytes - 7-10
	FileWrite($hFile, 0x36);                   4 bytes - 11-14
    FileWrite($hFile, 40);                     4 bytes - 15-18
    FileWrite($hFile, Int($iW));                4 bytes - 19-22
    FileWrite($hFile, Int($iH));                4 bytes - 23-26
    FileWrite($hFile, Int(1572865));           2x2 bytes; 2bytes - 1, 2 bytes-24; 27-30
    FileWrite($hFile, Int(0));                 4 bytes - 31-34
    FileWrite($hFile, Dec(Hex($iMSize)));          4 bytes - 35-38
    FileWrite($hFile, 3780);                   4 bytes - 39-42
    FileWrite($hFile, 3780);                   4 bytes - 43-46
    FileWrite($hFile, Int(0));                 #########; 4 bytes of zeros - 47-50
    FileWrite($hFile, Int(0));                 #########; 4 bytes of zeros - 50-54
    FileClose($hFile)
	#EndRegion BMP Header part
	;
	
	$hKernel_Dll = DllOpen("Kernel32.dll")
	
    $stBuffer = DllStructCreate("byte[3]")
	$pBuffer = DllStructGetPtr($stBuffer)
	
	$tWritten = DllStructCreate("int Written")
	$pWritten = DllStructGetPtr($tWritten)
	
	$hFile = _WinAPI_CreateFile($sFile, 3)
    _WinAPI_SetFilePointer($hFile, 0, 2)
	
	$iMod = Mod($iW, 4)
	
	If $iMod > 0 Then
		$stMod_Buffer = DllStructCreate("byte[" & $iMod & "]")
		DllStructSetData($stMod_Buffer, 1, Binary(0))
		$pMod_Buffer = DllStructGetPtr($stMod_Buffer)
	EndIf
	
	If IsHWnd($hWnd) Then
		$iOld_Opt = Opt("PixelCoordMode", 0)
	EndIf
	
    For $j = $Y2 To $Y1 Step -1
        For $i = $X1 To $X2
            $sData = Binary(PixelGetColor($i, $j, $hWnd))
            DllStructSetData($stBuffer, 1, $sData)
            _WinAPI_WriteFileEx($hFile, $pBuffer, 3, $nBytes, $tWritten, $pWritten, $hKernel_Dll)
        Next
		
        If $iMod > 0 Then
            _WinAPI_WriteFileEx($hFile, $pMod_Buffer, $iMod, $nBytes, $tWritten, $pWritten, $hKernel_Dll)
        EndIf
    Next
	
	DllClose($hKernel_Dll)
	_WinAPI_CloseHandle($hFile)
	If $iOld_Opt <> -1 Then Opt("PixelCoordMode", $iOld_Opt)
EndFunc

Func _WinAPI_WriteFileEx($hFile, $pBuffer, $iToWrite, ByRef $iWritten, $tWritten = 0, $pWritten = 0, $vKernel_Dll = 'Kernel32.dll')
	Local $aResult = DllCall($vKernel_Dll, "int", "WriteFile", "hwnd", $hFile, "ptr", $pBuffer, _
		"uint", $iToWrite, "ptr", $pWritten, "ptr", 0)
	$iWritten = DllStructGetData($tWritten, "Written")
	
	Return $aResult[0] <> 0
EndFunc

$hWnd = WinGetHandle("[CLASS:Progman]")