hi i'm not about to start coding for you, but even with a fairly limited grasp of perl you should be able to create a simple autoupdater. unless I'm missing something here all you would need to create would be a script that logs on to your main server, checks for the update file (opens it & reads it to check it is a needed update, or just datename the file) and then downloads it and inserts/overwrites where necessary. run it on a cronjob at whatever time you want and hey presto, I doubt it would be more than 50 lines (and thats my appalling coding effort).
hope that helps (in a little way :))
t