I'm not sure you can do what you are trying to do, exactly as you describe it.
The best I think you can get, is opening it like an anchor tag could.
Link
But I don't think this provides the functionality you need
EDIT
http://www.w3schools.com/jsref/met_win_open.asp
This link gives some insight on the window.open
Under the parameter values, you have :
name Optional. Specifies the target attribute or the name of the window. The following values are supported:
_blank - URL is loaded into a new window. This is default
_parent - URL is loaded into the parent frame
_self - URL replaces the current page
_top - URL replaces any framesets that may be loaded
name - The name of the window (Note: the name does not specify the title of the new window)
Maybe you have tried these, maybe not, but this parameter might be able to do what you need