Sorry, there is no such thing
We've been looking at this idea for years, ever since these devices first came out. Nobody has ever figured out a way to use anything but a built in FD for other than the top end PSR's for loading styles, other than some pretty flakey jury rigged things, or the much better (and CHEAP) OneManBand program.
http://www.home.zonnet.nl/JosMaas/onemanband/reactions.htm Bob