While we could sync a shared FTP or other folder, the posts about accounting run off a network share has me writing you may be really upset on the results.
That said, is the folder small enough to put on Dropbox and let Dropbox do it's magic?
Remember that with so many blowing up their accounting files on a network share, let's hope you know enough to not try that. Just sync to a network FTP share like FileZilla and your choice of syncing.
I used to only use PC and I have been using Mac's for the last 10 or so years. But I still have PC's for certain programs.
Here is my issue: I have a PC laptop that runs some accounting software on Windows 7. I have another Mac computer that is running Windows 7 on Parallels Desktop. I need for the accounting software running on W7 inside the Mac to see the folder/s on the PC to share the data. While both computers are technically on the same network, they are not because the Mac computer is supplying the Parallels version with the internet. So the Parallel W7 thinks it has an ethernet connection.
I am mostly positive that this is why Workgroups do not work. But as I have said I am so far out of the loop I really no longer no much at all about administering a PC.
How do I let the two operating systems see each other and share folders?
Any help would be appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic