Batch / Find And Edit Lines in TXT file

Question

I want to create a batch while which finds specific lines in a batch file and are able to edit these lines.

Example:

//TXT FILE//

ex1
ex2
ex3         


        

Answer 1

@echo off
set "replace=something"
set "replaced=different"

set "source=Source.txt"
set "target=Target.txt"

setlocal enableDelayedExpansion
(
   for /F "tokens=1* delims=:" %%a in ('findstr /N "^" %source%') do (
      set "line=%%b"
      if defined line set "line=!line:%replace%=%replaced%!"
      echo(!line!
   )
) > %target%
endlocal

Source. Hoping it will help some one.