@Echo Off & setlocal EnableDelayedExpansion
cd.>c.txt & set /a n=0
For /f "delims=" %%a in (a.txt b.txt) do (
set /a n+=1, m=n %% 2
If !m! equ 1 (
set "var=00%%a"
) else (
set "_!var:~-11!=%%a"
)
)
For /F "tokens=* delims=0_" %%a in ('set _') do (
For /f "tokens=1* delims==" %%i in ("%%~a") do (
Echo %%i& Echo %%j& Echo\
)
)>>c.txt
start "" "c.txt"