There might be some apps that help with that on the Play Store, but I'm not entirely sure. Most of the time a custom launcher will have backup settings, and those backups stay on your SD so they should be there even if you factory reset from recovery. Check with your specific phones user guide though just to make certain.
Edit: You may have to re-add widgets manually.
If you format the sd card, that wipes everything from it (not to be confused with wiping data/factory resetting in recovery). Most people use DropBox (over WiFi) or something similar to make extra backups on their PC or laptop hard drive. If that's the case, or however you moved your backups, yes you should be able to move them back to the SD.
I hope I understood your question, and that I was able to help!