As I said in my post I'm trying to shortcut viewing the history. I've not had luck setting a report file in the scan settings but I'll try again. Will the scan settings accept a path, eg: C:\Users\admin\Desktop\Filename?
Whilst I have never tried to set a location, but I believe it only allows you to set a file name, by leaving the * for the file name, that takes the file name from the Scan name, so it should make it easier to find. If it were to allow a folder selection, I would assume it use the explorer style navigation window to select the folder.
However, your example (even if it allowed folder selection) of trying to place it in the admin sub-folders, I suspect that it would block that anyway unless you were running/logged on as the admin. Not trying to teach you to suck eggs - Generally it isn't advised to run as admin unless you have a specific task that requires it.
As you mentioned - Scan logs are located in the C:\ProgramData\AVAST Software\Avast\report folder - but I believe that is where the scan history would get its data from.