There are no macros like in GSAK on PGC for users. Because there are many types of car GPSes I suspect the better solution it to use an external services.
I have never tried it but a quick web search results in many hits if i look for gpx to poi (for the garmin case) both web and desktop resources
I suspect there exist guides/services to convert PQs to use in car GPSes for people that don't use GSAK