Sorry, overlooked the ftp in the thread title... Well, in theory all you need to do is set up an FTP server on the 2k3 server with something like
Filezilla Server. Ive been told it isnt all that hard, but I never had to use it since most machines which support ftp come with their own little app...
I dont have a lot of time right now, but setting it up seems straightforward enough. I might have more time later today and I will see if I can post an example configuration :)
EDIT: Seems it IS really easy. Just install it (DONT choose port 21 or the server will not be able to start), start the server configurator, click ok, set up a user with an assigned shared folder and in theory the machine should log on to the server, send its file and the server should automatically place it in the specified shared folder.
You might have to edit the PASV (passive mode) settings though if a router/firewall is present in the network... let me know if it works! :D