Thank you both @dfyt5 and @DFELD2005
I finally found out where the error was. The original code I posted was usable with one exception. I had to jump a line after test.mp3. I’ll explain more in case other users read this.
So this is correct:
#EXTM3U #EXTINF:1024,test.mp3 test.mp3
This is NOT correct:
#EXTM3U #EXTINF:1024,test.mp3 test.mp3
This can be made with Mac if using for example TextMate which allows to choose which line ending to save in.
DFELD2005’s batch file code also worked of course. So I could simply save the file using TextMate as
D:\Music\Testing\test.mp3
Gonna look for a freeware for Mac which allows to choose line endings. Suggestions are appreciated 
