@echo off
set count=1000
for /f "delims=" %%a in ('dir /s /b /a-d "A"') do (
set /a count+=1
call ren "%%a" "A-%%count:~-3%%.jpg"
)
set count=1000
for /f "delims=" %%a in ('dir /s /b /a-d "B"') do (
set /a count+=1
call ren "%%a" "B-%%count:~-3%%.txt"
)
set count=1000
for /f "delims=" %%a in ('dir /s /b /a-d "C"') do (
set /a count+=1
call ren "%%a" "C-%%count:~-3%%.ddb"
)
set count=1000
for /f "delims=" %%a in ('dir /s /b /a-d "D"') do (
set /a count+=1
call ren "%%a" "D-%%count:~-3%%.dwg"
)