Edit in JSFiddle

(function ($) {
    $('#add_at_position').on('click', function () {

        var text_to_add_at_position = $('#text_to_add_at_position').val();
        var position = $('#position').val();

        if ($.trim(text_to_add_at_position) == "" || $.trim(position) == "") return;

        $("<option value='" + text_to_add_at_position + "'>" + text_to_add_at_position + "</option>")
            .insertBefore($("#languages5")
            .find("option")
            .get(position - 1));

    });
})(jQuery);

<label for="">Text to Add</label>
<input type="text" class="form-control" id="text_to_add_at_position">
<label for="">Position</label>
<input type="text" class="form-control" id="position" style="width:50px" value="3">
<input type="button" value="Add" class="btn btn-primary" id="add_at_position">
<div class="code_example">
    <select name="languages" id="languages5">
        <option value="c">C</option>
        <option value="c++">C++</option>
        <option value="php">PHP</option>
        <option value="perl">PERL</option>
        <option value="ruby">RUBY</option>
        <option value="python">PYTHON</option>
        <option value="go">GO</option>
    </select>
</div>