Why not just copy and paste the file?, rather than all that hassle?
The second time you run it, it will only copy new and updated files.
You can also use Task Scheduler to run this command, personally, I like having a link on the Desktop that I can double click to start my backup.
IMO, it's safer to do backups like this, RAID1 can't undo deletion mistakes etc.
I typed all that up so you could grasp how to use a batch file.
A copy/paste job will take longer than robocopy and will prompt you for existing files etc.