How to replace a string in the host file using batch?

Question

I'm trying to write a batch file to find and replace an IP address in the hosts file.

I did a bit of research and found this, but it doesn't seem to work. I get the final echo of "Done." but it doesn't work.

@echo off

REM Set a variable for the Windows hosts file location
set hostpath=%systemroot%\system32\drivers\etc
set hostfile=hosts

REM Make the hosts file writable
attrib -r %hostpath%\%hostfile%

setlocal enabledelayedexpansion
set string=%hostpath%\%hostfile%

REM set the string you wish to find
set find=OLD IP

REM set the string you wish to replace with
set replace=NEW IP
call set string=%%string:!find!=!replace!%%
echo %string%

REM Make the hosts file un-writable
attrib +r %hostpath%\%hostfile%

echo Done.

Answer 1

@echo off

REM Set a variable for the Windows hosts file location
set "hostpath=%systemroot%\system32\drivers\etc"
set "hostfile=hosts"

REM Make the hosts file writable
attrib -r -s -h "%hostpath%\%hostfile%"

REM set the string you wish to find
set find=OLD IP
REM set the string you wish to replace with
set replace=NEW IP

setlocal enabledelayedexpansion
for /f "delims=" %%a in ('type "%hostpath%\%hostfile%"') do (
set "string=%%a"
set "string=!string:%find%=%replace%!"
>> "newfile.txt" echo !string!
)

move /y "newfile.txt" "%hostpath%\%hostfile%"

REM Make the hosts file un-writable - not necessary.
attrib +r "%hostpath%\%hostfile%"

echo Done.
pause