[gora]

Код:

@Echo Off
SetLocal enabledelayedexpansion
Set src=C:\1234cv01.rar
Set out=c:\arhiv

For /L %%i In (0,1,99) Do (
	Set nb=0%%i
	Set nb=!nb:~-2!
	If Not Exist "%out%\1234rn!nb!.rar" (Move "%src%" "%out%\1234rn!nb!.rar" & Exit)
)