I'm trying to control a volume track bar but, until now I managed only to move the slider without changing the volume. This is the code that I used:
const uint TBM_GETPOS = 0x0400;
const uint TBM_SETPOS = 0x0405;
const int intCID = 10102;
public static void control_sopcast(IntPtr handle, int val_volume)
    {
        IntPtr pControl;
        IntPtr cControl;
        pControl = FindWindowEx(handle, IntPtr.Zero, "#32770", null);
        cControl = GetDlgItem(pControl, intCID);
        SendMessage(cControl, TBM_SETPOS, 1, val_volume);
SendMessage(pControl, WM_HSCROLL, 5, (int)cControl);
    }
Can someone help me with this? Thanks.