how to create/initialize the file object using file path html5

there is many examples of reading local files using html5 but by choosing from list of files , my problem is that i want to create the file object manually , think about i have a file with the link

file:///G:/Users/txt.txt

i want the browser to open it ,

i think it have to File f=new File('file:///G:/Users/txt.txt');

my question is how to create/initialize the file object using file path ?!