Код:
@(SETLOCAL EnableDelayedExpansion
set "TYPE=N"& for /f "usebackq delims=" %%a in ("file.txt") do @(set "$a=%%a"
if not "!$a!"=="!$a:[start_text]=!" set "TYPE=Y"
if not "!$a!"=="!$a:[end_text]=!" set "TYPE=N"
if not "!$a!"=="!$a:var=!" if "!TYPE!"=="Y" echo !$a!
))>"exit.txt"
