Open Directory implementation

Good morning!
I am getting ready to implement an Apple Xserve in our environment and was wondering about how to integrate my Windows servers with it. We do not have an Active Directory tree at all, just a Windows Workgroup. Will I be able to add my Windows servers as File Servers to the Open Directory structure??? Or will they only be able to authenticate to the domain???

I haven’t been able to find a whole lot of documentation other than that stating you can integrate with Active Directory.

thanks!
Mike