Zencart XML export

I am looking for someone to create a php page that I can add to my zencart admin backend that will allow me to customize and export products from my store into XML format on a schedule. I need to be able to schedule the export (cron), so settings need to be retained (email address, id, category and will be the same for all items, regardless of city. Date 'since' needs to be dynamic (date of export). SourceURL needs to be pulled from ZenCart database for each product. Attached is an example of the xml output format that I need. The fields in RED will need to be customizable through the php page, either text box (email address, id, category, etc.) and be able to pulled from a db table. The 'cities' and city urls are static, but there are lots of them. Additional tables can be added to the zencart database, but I do not want 'native' zen cart tables modified. I would like each item to be exported once for each city, with the appropriate changes. As this is a live storefront, I can supply a subset of the zencart database for offline testing.