我正在努力使我的同类与国际角色合作。然而，当我尝试排序时，它被弄乱了，顺序不对。下面是我的代码：

function character_substitute(string) {
    var first_char = string.replace( /<.*?>/g, "" ).toLowerCase().charAt(0);
    var chars = /[šđžčć]/g;

    if (first_char.match(chars)) {
        if (first_char == "š") { first_char = first_char.replace("š", "s"); return first_char; }
        if (first_char == "ž") { first_char = first_char.replace("ž", "z"); return first_char; }
        if (first_char == "č") { first_char = first_char.replace("č", "c"); return first_char; }
        if (first_char == "ć") { first_char = first_char.replace("ć", "c"); return first_char; }
        if (first_char == "đ") { first_char = first_char.replace("đ", "d"); return first_char; }
    }

    return first_char;
}

jQuery.fn.dataTableExt.oSort['balkan_string-asc']  = function(a,b) {
    x = character_substitute(a);
    y = character_substitute(b);

    return ((x < y) ? -1 : ((x > y) ? 1 : 0));
};

jQuery.fn.dataTableExt.oSort['balkan_string-desc'] = function(a,b) {
    x = character_substitute(a);
    y = character_substitute(b);

    return ((x < y) ? 1 : ((x > y) ? -1 : 0));
};

$(function() {
    $("#example").DataTable({
        columns: [{
            type: 'balkan_string',
            targets: 0
        }]
    });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://cdn.datatables.net/1.10.25/js/jquery.dataTables.min.js"></script>
<link href="https://cdn.datatables.net/1.10.25/css/jquery.dataTables.min.css" rel="stylesheet" >

<table id="example">
    <thead>
        <tr>
            <th>String</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>aaaa</td>
        </tr>
        <tr>
            <td>bbbb</td>
        </tr>
        <tr>
            <td>cccc</td>
        </tr>
        <tr>
            <td>čččč</td>
        </tr>
        <tr>
            <td>ćććć</td>
        </tr>
        <tr>
            <td>dddd</td>
        </tr>

    </tbody>

</table>

这是尝试排序时的输出：

dddd
cccc
čččč
ćććć
bbbb
aaaa

顺序应如下所示：

dddd
ćććć
čččč
cccc
bbbb
aaaa

有办法解决这个问题吗？我没有找到解决问题的办法，所以我试着自己写。
有人能帮我吗？