@echo off
type nul>out.txt
setlocal enabledelayedexpansion
set n=0
for /f "delims=" %%i in (in.txt) do (
set "d!n!=%%i" & set /a "n=(n+1)%%3"
if !n! equ 2 if not "%%i"=="count" echo.!d0!>>out.txt&set n=1& set "d0=%%i"
if !n! equ 0 echo.!d0! !d2!>>out.txt
)

!d0!と!d2!の間は普通にtab入力