Auto Update .dat file on website

I'm looking for a script or something that would automate my product store site: [login to view URL] The admin portion of the site has the cability of uploading a .dat file that loads all the current inventory, product descriptions, etc. What I need is the ability for when the site that has all the products: [login to view URL] is for the .dat file to be updated every week or so. Can a script automatically go out and download the file from [login to view URL] and then upload the file to [login to view URL] You can see the downloadable files here. [login to view URL] Can you make sure that this can be done for the pictures and the data. As with my site now, the pictures have to be uploaded first, then the .dat file with all the information. I do have cron enabled on my host.