All SatNavs use POI files with a set file suffix ie .csv or .ov2, etc. Each SatNav manufacturer uses a different suffix. If you can convert one suffix into another suffix then, in theory, you can use any POI file designed for one SatNav to be used by any other manufacturer.
POI Edit is a free download which very simply accomplishes this transformation
http://www.poiedit.com/
Your grandsons will be able to show you how it works.