XML Export and Import from FTP server

We need one program that do the below things. in example i'll call this program name "A". then the have another accounting program name "B". so all the sales from A will need to export out in .XML format, then upload to FTP server, then B will download this XML file from ftp server to do the accounting ... so we need to create the scrip for them to auto grab the XML fil from A, then upload to their ftp server, then the scrip will also download the XML file to input into B... all this have to be done in automatic, no manually do... coz it's all 78 outlet, means script will export 78 outlet from A, then import 78 outlet data into B Let me know if anyone can do the things. Regards, Rahul