You can indeed. mklink.exe is your friend here.
It sounds like you want to create hard links for your files in all of your projects, so you would start with one of the files and create hard links to the other directories. At this point, all of the file names will be pointing at the same chunk of data. You could create symlinks as well, but I think a hard link fits your model better.
mklink /h linkname targetpath
You can also use it to create directory links, which will behave slightly differently as there will be one real directory, and the links will point to it.
mklink /d linkname targetpath
Further details at What are the various link types in Windows? How do I create them?