The Scripts:
plesk1:~# cat /opt/psa/scripts/domain.php 
#!/usr/bin/php
<?php
/*
 Command Options
  -a <action>
    up - Update Domain Name (requires arguments n and o)
    add - Add a new Domain Name (require arguments n)
    del - Delete an existing Domain Name (requires argument o)
  -o <domain>
    old domain name to work on
  -n <domain>
    new domain to work on
*/

$url = 'http://ns0.element9.net/domain.php';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
$options = getopt('a:o:n:');
curl_setopt($ch, CURLOPT_POST, true);
$fields = '';
$fields .= 'server='.rawurlencode('plesk1');
$fields .= '&key='.rawurlencode('uniquekey');
$fields .= '&action='.rawurlencode($options['a']);
$fields .= '&old_domain_name='.rawurlencode($options['o']);
$fields .= '&new_domain_name='.rawurlencode($options['n']);
curl_setopt($ch, CURLOPT_POSTFIELDS,$fields);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result= curl_exec ($ch);
curl_close ($ch);
$result = explode('|',$result,2);
if ($result[0] == 'SUCCESS') exit(0);
if ($result[0] == 'ERROR') print $result[1]."\n";
else print "Unknown output\n".$result[0]."\n";
?>
plesk1:~# 

=Event Manager Settings=
Domain alias created	lowest (0)	psaadm	/opt/psa/scripts/domain -a add -n <new_domain_alias_name>
Domain alias deleted	lowest (0)	psaadm	/opt/psa/scripts/domain -a del -o <old_domain_alias_name>
Domain alias updated	lowest (0)	psaadm	/opt/psa/scripts/domain -a up -o <old_domain_alias_name> -n <new_domain_alias_name>
Domain created	lowest (0)	psaadm	/opt/psa/scripts/domain -a add -n <new_domain_name>
Domain deleted	lowest (0)	psaadm	/opt/psa/scripts/domain -a del -o <old_domain_name>
Domain updated	lowest (0)	psaadm	/opt/psa/scripts/domain -a up -o <old_domain_name> -n <new_domain_name>