Find the control XPath on Focus in WebBrowser control

I had developed a windows application with WebBrowser control, which can interact with windows control using this sample provided

http://msdn.microsoft.com/en-us/library/system.windows.forms.webbrowser.objectforscripting.aspx

But my need is when user focus an control, that controls XPath need to be send to my w开发者_开发百科indows application

For that two main needs are their

1. Need to set javascript event to all controls (can it be commonly configured in single control)
2. that javascript need to find xpath and send

Can any one help me in doing this