I have been trying to convert REG's from a PSR 2000 to the PSR S950 RGT without success. I don't think there is a program doing that.
As Gary said, I used an Floppy-USB drive to copy floppies to a PC. If the extension on your keyboard is also REG instead of RGT you can more or less forget it. Even not in Murray's famous converting prog, there is no choice.
However if the extension is RGT you can load them into the 950 BUT you need quite a bit of tweaking.
Dick