This guy saved my day!!!
The problem was that Windows could not interpret the file as UTF-8 on itself. it reads it as asci and then ä becomes a 2 character interpretation ä (ascii 195 164)
trying to convert it, I found a solution that works for me:
iconv -f UTF-8 -t WINDOWS-1252//TRANSLIT --output=outfile.csv inputfile.csv
now I can view the special chars correctly in editors
For SQLServer compability, converting UTF-8 to UTF-16 will work even better ... just the filesize grows quite a bit