Searches folder and subfolder, the content of each file for the specified string, then prints the filename, and line+character offset. To use regex, add the /r flag to both findstr checks.

search.bat

@echo off
:start
echo =============
echo New Search
echo =============
set /p "search=Search String:"
echo --
findstr /s /m %search% *.*
echo ----------
echo \\\\\\\
echo Details
echo ///////
echo ----------
findstr /s /n /o /p %search% *.*
echo =============
pause
goto start