How can I make sure this script does not use text from the file name as an option in the zip string?

:create_zip
$cmd=" wzzip -a -ex -rp "
$cmd=$cmd+' "$basedir\'+LTRIM(RTRIM($filename))+'.zip" "$basedir\'+LTRIM(RTRIM($filename))+'" '
SHELL '%comspec% /c $cmd '

Thanks Heaps
Phoe