I would like to access a folder of mp3 files on my local Windows machine through http:// addresses. For example, typing http://localhost:9999/songs/test.mp3 into my browser would play test.mp3, which sits in a specified folder on my C: drive. What is the very simplest way to do this?

(Background: a program I'm using wants me to enter the URLs of these files, but assumes they are remote and accessed over http. It doesn't accept URLs of the form file://C/Users.... So, I'd like to give these local files addresses that makes them "look" remote.)