Processing CSV file

I have the following use-case and I am wondering how I could achieve it with WSO2 ESB, WSO2 BPS and any other modules/products (maybe Data Services?): I have a CSV file which is generated periodically by System A. I need to detect the presence of this file (maybe by polling every 5 minutes or so), parse this CSV file (which has multiple records), and for each line (record), transform it into an XML request and feed it to a BPEL process which invokes System B and System C together with some business process logic. The file needs to be moved to another folder or deleted, so that it is not picked up with the next poll. The outcome of each BPEL process instance then needs to be saved to another CSV file, such that for each input file I have an output file with the results, with both files having an identical number of records. I was thinking of using the VFS to poll for new files and write to the output, but I am a bit lost how to do the whole chain to achieve the above. I am a bit new to WSO2 ESB and BPS, so please do not assume I know too much about how to do things.