Follow chascoadmin reply. You should be able to reproject your CSV file in different CRS with QGIS. If you are familiar with R, you can do it there too.
If you want to do post-processing of the rover data, you will definitely need base log file. After it, try using my tool for getting points back from your log file. You can find it here:
Just input your pos file and csv file and you are ready to go.
