Creating a virtual file system

[Atila Olah]

I'm working on a project to implement a simple cross-platform file
sharing protocol (using Python) that is similar to HTTP, and I have to
write a GUI for Windows and Linux. But let's start with the harder one:
Windows.

My question is: How do I implement a virtual partition that acts like a
real file-system and is compleatly transparent to other programs?
Should I make a virtual file allocation table for a FAT32 partition or
simulate an NTFS? Or even further: How do I create a junction (or a
hard link) to it in "My network places" or in "Entire Network"?

If there are tools that could help me but written in C or C++, please
let me know, I'll compile them to Python modules.

Thanks forward for help.