I don't think anyone has a sensible answer.
So here's is what I always do.
- Copy /appdata/roaming/ folder into Dropbox say, D:\DropBox\roaming
- Then delete the original C:\...\roaming\ folder
- After that You have to create a symlink/junction from D:\DropBox\roaming to C:\Users\root\AppData\Roaming\
- I use this tool : http://schinagl.priv.at/nt/hardlinkshellext/linkshellextension.html
- NOTE : sometimes files don't sync if you just create the junction from the Original folder to Dropbox ( I don't know why) You can always give it a try. Just create a juction from appdata/roaming/ into Dropbox/roaming and see what happens.