Opening Polylines in other software products (for coordinate reprojections)

I want to use a region of a Leapfrog model for a different Leapfrog model. These models use different coordinate systems. Reprocessing the boreholes and geological maps etc. is no problem but I have constructed many polylines for manual editing.

Since Leapfrog can't do reprojections I am considering to export all polylines, reproject these with a different software and then import these reprojected polylines again. However, so far, I could not find any software product which is able to import these polylines (consisting of oriented lines and oriented points).
Do you have any ideas or recommendations? Maybe editing the coordinates listed as a csv export?

Thanks in advance