KiX already supports this with version 4.53 using the /p switch.
Basically no program can delete in-use files until a reboot or by attempting to kill the process, which is often not a good idea.
Action: Deletes one or more files.
Syntax: DEL "file name" [/c] [/f] [/h] [/p] [/s]
/c Continue deleting files, even if error(s) occur.
/f Delete read-only files.
/h Deletes hidden and system files also.
/p Postpone action until next system reboot.
/s Delete specified files from all subdirectories.
Remarks: DEL does not prompt the user to confirm the deletion.
Wildcards are supported.
