My unix system has Samba installed. All I have to do is to mount a Windows share, say, C:\Inbox, to /mnt/inbox on my Unix system:

The command is:

mount -t smbfs -o username=Roger,password=Blah //luke/inbox /mnt/inbox
[download]

Then you can write to your share from Unix as if it's a local unix directory.

Oh, by the way, your windows drive should be formatted with FAT32. Smbfs will only mount an NTFS partition as readonly.