JSFiddle - React, Tailwind, and code Playground

JavaScript

var subject = 'href="{{$myparam}}" or any other {{$myparam}}';
var regex = /"[^"]*"|(\{\{(.*?)\}\})/g;
var match = regex.exec(subject);

replaced = subject.replace(regex, function(m, group1) {
    if (typeof group1 == 'undefined') return m;
    else return "<span class='highlight'>" + group1 + "</span>";
});
alert(replaced);