Infragistics Listbar: How to change item image on mouseover

Hello,

I'm using an Infragistics Listbar and I'm wondering what's the best way to change an item's image when the mouse moves over it.  I tried this:

private void ListBar_MouseMove(object sender, MouseEventArgs e)
{
   System.Windows.Forms.Control c = this.ListBar.GetChildAtPoint(e.Location);
   //then I'll somehow cast c as a listbar item and change the image...
}

but c is always null.  I'm surprised that this functionality isn't already built into the control, but I can't find any useful examples and the help isn't very helpful.  

I'm new to C# but I've been developing in other languages for a while (most recently VB6).

Any help is appreciated.  Thanks!