DEL /a: /e /z whatever.ext

[C:\]del /a: /e /z "C:\Backup\Program Files (x86)\Common Files\Microsoft Shared\DAO\dao360.dll"
Deleting C:\Backup\Program Files (x86)\Common Files\Microsoft Shared\DAO\dao360.dll
     0 files deleted       1 failed

[C:\]attrib "C:\Backup\Program Files (x86)\Common Files\Microsoft Shared\DAO\dao360.dll"
___A_____________  C:\Backup\Program Files (x86)\Common Files\Microsoft Shared\DAO\dao360.dll