gistfile1.txt

@echo off
IF [%1]==[] (
echo renumber01.cmd filemask filename
echo                bis_*.bmp bis
echo                		  bis01.bmp bis02.bmp bis03.bmp ...
echo ------------------------------------------------------------------------------------
) ELSE (
setlocal EnableDelayedExpansion

set prefix = %2

for %%a in (%1) do ( set /a i+=1 )
echo %1: !i!

set /a i = 1

for %%a in (%1) do (

set newname=00!i!
set newname=!newname:~-2!

set /a i+=1

echo %%a = %2!newname! // !pre!
ren %%a %2!newname!.*
)
echo ------------------------------------------------------------------------------------
)