If it is, please let me know how ;-)…
I´m not exactly sure if this is what you are talking about, but when exporting audiofiles via the export–> Audio Mixdown menu, you can embed markers to the audio file via the “insert Marker Chunk” checkbox:
When importing this audiofile to a new Nuendo project, you can extract those markers via Menu Audio–> Advanced–> Extract Markers form Wave File:
Edit: Those markers are recognised by Wavelab and Spectralayers
Thank you Wolfger,
that was the procedure I´ve used but I now found by conicidence what my problem actually was 
.
Before, I was trying to load the file with marker chunks activated into a Montage in WL 13 and it didn´t show the markers. That´s why I thought it doesn´t work.
I now just opened it as an audio file … and there they are!
I now have to ask PG why these markers don´t show when added to a Montage…