There is a setting which can be set in the php.ini file called arg_separator.input. If you don't have access to the php.ini file, you can access the query string through $_SERVER['QUERY_STRING'] and use explode to set up your array:
PHP Code:
<?php

function parse_custom_query_string($arg_separator ';'$value_separator '='
{
    
$_GET = array(); // clear old $_GET array

    /* separate query string uising the arg_separator */
    
$pairs explode($arg_separator$_SERVER['QUERY_STRING']); 

    
/* loop through each name vlaue pair */
    
foreach($pairs as $value) {
        
        
/* ignore if no value separator is present */
        
if (($pos strpos($value$value_separator)) === false) {
            continue;
        }   

        
/* extract and decode each componenet */
        
$name urldecode(substr($value0$pos));
        
$value urldecode(substr($value$pos +1));

        
/* add to the $_GET array */
        
$_GET[$name] = $value;
    }
}

parse_custom_query_string();
?>