If you followed the directions in the other post which I referred you to, you should have probably used TotalCommander (under Windows OS) to decode the backup file.
Then as the post also explains, you would then have a series of .bin files which you would rename to .tar.gz. There generally will be 3 files per domain which you will want. One holds the domain root, another has the Maildir, and the 3rd has the conf/errordocs/pd/statistics directory contents.
Some of the smaller 1k, 2k files are probably not readable, but the other larger ones can then be read using WinRAR and extracted so you can have the files, and see what is contained within each .tar.gz file.
Upload the ones you need to the cPanel server (as .tar.gz files), then use the linux utils to uncompress them.
You could use other Mime Decoder programs as well. See the other post for additional links.