Text file conversion for upload to Strava

I have a text file (.dat) with over 1400 lines representing some basic information about over 1400 runs and bike rides stretching from 2002 thru 2011. I would like to import that data into Strava. Strava only imports .tcx, .fit or .gpx files. I believe a script that will read the text file entries and put select fields from each line into the appropriate place in one of the accepted import file formats would be sufficient. Delivery could be either a functioning script(app) to do the conversion, or over 1400 individual files.