This is something we could help with in a premier support ticket.
You would probably want to use a url more like this: http://www.quiru.es/clients/name-client/
So that you can have other pages on your site... You would want at least one "itentifier" in the url, in this case /clients/ that the mod rewrite can key off of.
Then the rule would be something like:
RewriteRule ^clients/(.*)$ renovaciones-detalles.php?aloName=$1
But that is still going to create the url like:
So you would have to update the the renovaciones-detalles.php page to do the lookup based on the client name and not the id.