Ok, finally I've been bothered to get some software written and released. It's a RoadRunner plugin & you can find the details here JoyVol Plugin
I try it myself if I can get it work.
I did. For a start, it doesn't work with game ports & secondly its digital not analogue. Take a read through this thread & see what I'm trying to achieve.
Anyway to get something like this working on a modern PC with no gameport relatively easily?