Timo, thanks a lot, it is working fine now.
I also tried PGN129285 and PGN130074 to get position of the next waypoint.
But, with this two PGN´s I got a compiling error with the line
if (ParseN2k...
As I can see in N2kMessages.H, this data is probably stored in a database.
Do yo have an example, how to read such a database?