In Visual Basic .Net, I am trying to figure out how to
get a reference to the open window that the mouse is in.  
Suppose I select (highlight) text on a web page shown on
an Internet Explorer window, and then click on a toolbar
item in that window which runs my VB program, and the VB
program will copy the highlighted text to the clipboard.  
I know how to use ShellWindows to loop through the
different open windows, but how can I determine which
window was the one the mouse was in when the VB
application was started?

I've tried using GetAcitveWindow in the API, but it
returns a 19-digit number.  Is there a way to convert
this to the 6-digit HWND, or is there an alternative
solution?