You can find the saves on mac in the \Game.app\Contents\Resources\app.nw\save folder, Try to copy the entire content, including the global and config file, into the www/save folder of the windows version.
I'm not 100% certain, but I think the saves between mac and windows are compatible.
I've been trying to do as you said for hours now, but it doesn't seem to be working. I'll keep on trying though.
Also, for the windows version, it seems like I have to extract the game.exe file every time i want to play the game, and I can't run it whenever pull it out to my desktop or anywhere else other than the original zip it was downloaded in. Is there anyway to fix this?
*Whenever I have the game.exe on my desktop/etc and click on it, it gives me an error message that goes
"The code execution cannot proceed because nw_elf.dll was not found. Reinstalling the program may fix this problem"; when the file nw_elf.dll was always present in the folder
i also tried deleting and reinstalling the file many times as what it says, but that doesn't help either