makebackup.bat

@echo off
 
set dtend=%date:~6,4%%date:~3,2%%date:~0,2%
 
 
for /f "eol=# delims== tokens=1,2" %%i in (makebackup.dat) do (
    set %%i=%%j
)
 
echo Working from %dt% to %dtend%
set arcname=promauto-src_%dt%-%dtend%.rar
 
rar a -ta%dt% %arcname% promauto-src
 
echo dt=%dtend%>makebackup.dat
 
move %arcname% F:\