Well, relative to your understanding of .bat or .vbs code, you can write something that does all you want with one click of some
specially created shortcut for your shutdown routine.
--down.bat--
REM ---backup the files
start /WAIT copy c:\myfile.txt d:\backupfolder
REM ---and out like a light
shutdown /s /f /t 00
--end file--
--down.vbs--
set shell = createobject("wscript.shell")
shell.run "copy c:\myfile.txt d:\backupfolder", 0, true
shell.run "shutdown /s /f /t 00"
--end file--
The Windows Script Host is especially good at handling the file system objects, if you care to get into it.
http://msdn.microsoft.com/library/en-us/script56/html/sgWorkingWithFiles.asp?frame=true