How can I format a URL that allows a browser app to access an html file on my sd card?

[Windows Central Question]

I have a sd card in my windows phone. I have upgraded to Windows phone 8.1. I can now access files on my sd card. I use set of html indexes on my sd card. I can use the Files application to access an open these files. I want to write a URL that I can use in a browser app to link to and open the html file.