C# Signature:

[DllImport("quickusb.dll", CharSet = CharSet.Ansi)]
    static extern int QuickUsbOpen(out IntPtr handle, string devName);

Notes:

Make sure devName="QUSB-0\0\0";

Tips & Tricks: Please add some!

Sample Code:

private IntPtr handle;
string deviceName="QUSB-0\0\0";

int result = QuickUsbOpen(out handle, deviceName);