RewriteCond %{HTTP_USER_AGENT} ^(Mozilla¦Opera)
RewriteCond %{HTTP_USER_AGENT}!(Slurp¦surfsafely)
RewriteRule ^robots\.txt$ /someotherfile [L]

User-agent: *
Disallow: /css
Disallow: /add.php
Disallow: /conf.php
Disallow: /confindex.php
Disallow: /edit.php
Disallow: /delete.php
Disallow: /addcontent.php
Disallow: /list.php
Disallow: /clist.php
Disallow: /cedit.php
Disallow: /cdelete.php
Disallow: /content.php

# End robots.txt file