Default [Q] File recovery in root folders? (/data/)

I just lost one off my app's data (settings, etc, ...) and I'd like to try undeleting them. I know they were in the /data/data folder.
I found some file recovery apps on the store but it seems like they only scan the /sdcard/ folder.
I looked into mounting the sdcard on my PC and running a recovery software there, but mounting the root folder doesn't seem possible.

Any idea that might make this possible?