There's very little to be done in DOS these days that cant be done with suitable small programs.
Some time ago I asked here about batch files and the idea I picked up then was to use a neat freebie called EZBackitup. (There are others that do the same thing) This is the way I do what you might consider to keep everything backed up.
My Windows System files in fact the whole of C: drive is backed up using Acronis.
Not free, but very reliable and simple if you want a safe backup-restore system. If all data is kept away from drive C: then Acronis will accomplish the task more quickly.
EZBackitup will take care of the rest. When running it allows you to select exactly what you want to back up where it is saved. You can modify the behaviour - whether to overwrite delete or ignore older files and to save all this selection under a 'name.' When you want to use EZB, you open the application and click on the green tick. I backup data whenever I choose.
I try and remember to use Acronis about weekly, or sooner if I am making some significant change in the OS which might go sour, in which case the most recent Acronis file will have me safely out of the mess in about 15 minutes.
The destination could be anther HD internal or external or even a partition on your internal HD its a matter of your choice, just remember that if the Primary HD refuses to spin up one day, it is no use having your data backed up on a partiton of that disk.
Lastly though EZBackitup makes accessible copies, which can be read or copied at any time, Acronis when used to restore a crashed OS, would overwrite everything on the target, so that backup file must be saved on another drive and no the one that is being backed up.