{rdelim} and {ldelim} should work OK in this instance:
Code:
<script language="JavaScript" type="text/javascript" src="https://www.trackhelp.com/bin/ctrack.php"></script>
<script language="JavaScript" type="text/javascript">
<!--
var siteid = 1626; var proto = 'https';
if (typeof(valid) + '' != 'undefined') {ldelim}tlitrack(3,{$subtotal},{$order.orderid});{rdelim}
//-->
</script>