Here's the deal...

What would be the best way/methods to develope an applicaion to fit the following requirement?

40+ remote locations that produce a weekly file every Sunday. Each location has ISDN and runs on an NT platform.
Each file needs to be transmitted from the remote loation to centre, this can be either driven by centre or the remote locations.

Basicaly the files need to be 'polled' (If that's the correct word) weekly.

Any one got any ideas where to start or if there is software available to do this task?

Thanks in advance.