Any symbol to hex pattern, why ?

how to quickly make hex pattern like "~\xe2\x80\xb9~" from any symbol ?

i try brute force, but very long:

$s = 'Â';
$pat_all = '~[\x00-\xFF\x00-\xFF\x00-\xFF]~';
//die('stop');
if(!preg_match($pat_all,$s)) die("pat not found: ".$pat_all);
$i=0;
for($a=0;$a<256;$a++){
	$az = '';
	if($a<16) $az = '0';
	
	for($b=0;$b<256;$b++){
		$bz = '';
		if($b<16) $bz = '0';
		
		for($c=0;$c<256;$c++){
			$cz = '';
			if($c<16) $cz = '0';
			$pat = '~\x'.$az.dechex($a).'\x'.$bz.dechex($b).'\x'.$cz.dechex($c).'~';
			if(preg_match($pat,$s))die('found pat: '.$pat);
			//echo "\n<br>".$pat;
			if($i++==1000000) die('limit: '.$i);
			}
		//die;
		}
	}
die('end: '.$i.' pat: '.$pat);

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