Rename multiple folders with pattern in name using Batch

Question

I have 100 folders under a directory with naming in a pattern. Ex: DeDeP001M1TSub, DeDeP002M1TSub,...,DeDeP100M1TSub.

I am looking for a command line option to rename all the folders. I just want to change M1 to M2 as in DeDeP001M1TSub becomes DeDeP001M2TSub. I know of 3rd party applications that can do this, but am looking for a command line option to use in a bat file along with bunch of other stuff. Please help(Fairly new to the area)!!

So far have tried ren,mv but to no effect(not very familiar with dos scripting).

Answer 1

This should do it:

@echo off
setlocal enabledelayedexpansion

for /d %%a in (*) do (
  set "p=%%a"
  set "fp=!p:~0,8!" & set "tp=!p:~10!"
  echo ren %%a !fp!M2!tp!
)

Remove the echo once you verify the output is what you want to do the actual rename.