$share = "\\NAS\Volume_1\Database"
$date = get-date
$oldfilename = "MainDataStore"
$fileext = ".accdb"
$oldoriginalname ="MainDataStore.accdb"

$newfilename = $oldfilename + " " + $date.month + "-" + $date.day + "-" + $date.year + $fileext
copy-item "$share\$oldoriginalname" -Destination $share\Backup\$newfilename

# issue with this line
remove-item = $share\Backup\ + $oldfilename + " " + $date.month-2 + "-" + $date.day + "-" + $date.year + $fileext