Copy file to samba folder bat

NET USE Z: /delete
NET USE Z: "\\192.18.16.18\share\DB_Back\199" 

set sourceDir="D:\DB_Back\199\"
set targetDir="Z:\"
set dd=%date:~8,2%
set dm=%date:~5,2%
set dy=%date:~0,4%

set backupFileName=BK_DB2019_%dy%%dm%%dd%.bak
echo  start %backupFileName% %date% %TIME%
copy %sourceDir%%backupFileName%  %targetDir%%backupFileName%
echo  end %backupFileName% %date% %TIME%