iPhone: Click view behind transparent UIScrollView

Question

I have a UIScrollView that is set to have a clear background. Part of the scrollview does have content, but part does not (so it shows other views behind it). I would like to be able to click through the UIScrollView and to the MKMapView behind, but only for the transparent portion of the UIScrollView.

I have found some code which I am having a real hard time understanding how to get working:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if (![self yourMethodThatDeterminesInterestingTouches:touches withEvent:event])
        [self.nextResponder touchesBegan:touches withEvent:event]; 
}

Could someone help me wrap my mind around how to forward a touch event to a view that is behind another view? Can I call - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event from a UIViewController?