The "Drive C" Wine (PoL) installs the program to is virtual. I run Wine and it installs programs to my home folder within the hidden .wine folder.
/home/(your user name here)/.wine/drive_c
However Play on Linux has a slightly different set up, I think you will find your virtual drives in .playonlinux folder.
/home/(your user name here)/.PlayOnLinux
After that point, I am not sure where they set up the virtual drive, but it won't write to your Windows drive or any other drive.
Linux doesn't really identify drives as A: B: C: those are just for the Microsoft program to find its way. Linux uses device paths.
Meanwhile, if you are looking for a nice free Linux, Excel like spreadsheet, I would strongly recommend the Libre Office package. You can read all about it here https://www.libreoffice.org