Hi Randolph,
Thanks for your interest in Syncfusion products,
You can make use of the 'GetElementAtClientPoint' member of the HTMLUIControl to get the Location and Size of the element under the mouse pointer.
IHTMLElement element = this.htmlUIControl.GetElementAtClientPoint(e.Location);
A sample implementing this member is posted in the following thread,
http://www.syncfusion.com/support/forums/htmlui-windows/99990/Refer the sample and let us know if you need any further assistance.
Regards
Vallarasu S.