TeamCity on Windows, GIT repository in FileSystem

We are setting up a project with TeamCity. For demo purposes (before we install on the testing server) I´m trying to install TeamCity on Windows. We have our project in GIT, but the central repository is on a NT Fileserver (don´t ask )

The Git repository is on:

o:\dir\dir\project

I tried to enter a URL for the CVS Root in Teamcity:

file:///o:/dir/dir/project

but got an error when testing the connection:

The connection test failed:
org.spearce.jgit.errors.NotSupportedException: URI not supported: file:///o:/..../RailsApplication3

Do you have any idea on how to solve this?