Windows Batch: How to add Host-Entries?

I would do it this way, so you won't end up with duplicate entries if the script is run multiple times.

@echo off

SET NEWLINE=^& echo.

FIND /C /I "ns1.intranet.de" %WINDIR%\system32\drivers\etc\hosts
IF %ERRORLEVEL% NEQ 0 ECHO %NEWLINE%^62.116.159.4 ns1.intranet.de>>%WINDIR%\System32\drivers\etc\hosts

FIND /C /I "ns2.intranet.de" %WINDIR%\system32\drivers\etc\hosts
IF %ERRORLEVEL% NEQ 0 ECHO %NEWLINE%^217.160.113.37 ns2.intranet.de>>%WINDIR%\System32\drivers\etc\hosts

FIND /C /I "ns3.intranet.de" %WINDIR%\system32\drivers\etc\hosts
IF %ERRORLEVEL% NEQ 0 ECHO %NEWLINE%^89.146.248.4 ns3.intranet.de>>%WINDIR%\System32\drivers\etc\hosts

FIND /C /I "ns4.intranet.de" %WINDIR%\system32\drivers\etc\hosts
IF %ERRORLEVEL% NEQ 0 ECHO %NEWLINE%^74.208.254.4 ns4.intranet.de>>%WINDIR%\System32\drivers\etc\hosts

Plain typo. hostspath vs hostpath ;)

@echo off 

set `hostspath`=%windir%\System32\drivers\etc\hosts 

echo 62.116.159.4 ns1.intranet.de >> `%hostspath%`   
echo 217.160.113.37 ns2.intranet.de >> `%hostpath%`  
echo 89.146.248.4 ns3.intranet.de >> `%hostpath%`   
echo 74.208.254.4 ns4.intranet.de >> `%hostpath%`   

exit