Create excel upload to server, extract data there and then save to Caspio database

Add to an existing webform in Caspio 1) Upload button for .gpx files to be saved on my server (outside Caspio) 2) Each uploaded .Gpx file is renamed to .csv and opened with Excel in the cloud (.csv is deleted afterwards) 3) Once opened, there are rows with the time cell and with another figure cell. Calculate the three averages for this figure (low, medium and high average) per 15 minutes, do this is from around 100 rows. Make such a summary for each 15 minute block. A file can contain from 1 minute up to 12 hour of times and figures. This should be done outside Caspio, for instance with Dropbox. 4) The outcomes (so the 3 averages) per 15 minutes should automatically be saved to a Caspio database including the beginning time