capturecard change video source

[eukalyptus]

hi all,

i am using the webcamscript i found in the forum...

...
#include <GUIConstants.au3>
Opt("GUIOnEventMode", 1)
$avi = DllOpen("avicap32.dll")
$user = DllOpen("user32.dll")
$snapfile = @ScriptDir & "\scrshot.bmp"
$moviefile = @ScriptDir & "\moviecam.avi"
$Main = GUICreate("WebCam - Ready",350,300)
GUISetOnEvent($GUI_EVENT_CLOSE, "Quit")
$cap = DllCall($avi, "int", "capCreateCaptureWindow", "str", "cap", "int", BitOR($WS_CHILD,$WS_VISIBLE), "int", 15, "int", 15, "int", 320, "int", 240, "hwnd", $Main, "int", 1)

DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_DRIVER_CONNECT, "int", 0, "int", 0)
DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_SET_SCALE, "int", 1, "int", 0)
;DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_SET_OVERLAY, "int", 1, "int", 0)
DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_SET_PREVIEW, "int", 1, "int", 0)
DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_SET_PREVIEWRATE, "int", 30, "int", 0)
...

everytime i restart my computer the default video_in of my capturecard is set to composite-video...

i have to set the videosource manuelly to s-video.

DllCall($user, "int", "SendMessage", "hWnd", $cap[0], "int", $WM_CAP_DLG_VIDEOSOURCE, "int", 0, "int", 0)

this opens a popup window included in microsoft windows, where i can choose the right videosource...

is there a way to change the video-source directly with autoit-code without this popupwindow?

thxalot