URL rewrite in ASP.net for multi language

Solved this by writing my own URL rewrite module. Sample code for anyone who runs into similar problems is below. Decided to dump all other URL rewriting and route everything through this module instead.

Don't think this is easily possible with static rules.

public class DynamicURLRewrite : IHttpModule
{
    public void Init(HttpApplication context)
    {
        context.AuthorizeRequest += new EventHandler(context_AuthorizeRequest);
    }

    public void Dispose()
    {
        throw new NotImplementedException();
    }

    void context_AuthorizeRequest(object sender, EventArgs e)
    {
        var rw = new Rewriter();
        rw.Process();
    }
}

public class Rewriter
{
    public void Process()
    {
        using (MiniProfiler.Current.Step("Rewriter process"))
        {
            var context = HttpContext.Current;

            var rawURL = context.Request.RawUrl;
            var querystring = String.Empty;
            var urlParts = rawURL.Split('?');
            var url = urlParts[0];
            if (urlParts.Count() == 2) querystring = urlParts[1];
            if (url.StartsWith("/")) url = url.Substring(1);

            // Get language component
            Translation.Language inLanguage = null;
            {
                foreach (var lang in Translation.Language.GetAllLanguages())
                {
                    if (url.StartsWith(lang.LanguageTag, StringComparison.CurrentCultureIgnoreCase))
                    {
                        inLanguage = lang;
                        url = url.Substring(lang.LanguageTag.Length);
                        if (url.StartsWith("/")) url = url.Substring(1);
                        break;
                    }
                }
                if (inLanguage == null)
                {
                    inLanguage =
                        Translation.Language.GetLanguage(
                            Settings.Translation.ProjectReferenceVersionRequiredLanguageTag);
                }
            }

            // Querystring
            {
                if (!String.IsNullOrEmpty(querystring)) querystring += "&";
                querystring += "lang=" + inLanguage.LanguageTag.ToLower();
                querystring = "?" + querystring;
            }

            // Root pages
            {
                if (String.IsNullOrEmpty(url))
                {
                    context.RewritePath("~/pages/default.aspx" + querystring);
                    return;
                }
                if (url.Equals("login"))
                {
                    context.RewritePath("~/pages/login.aspx" + querystring);
                    return;
                }

And then some more complex rules:

            // Handlers
            if (url.StartsWith("handlers/"))
            {
                // Translation serving
                if(url.StartsWith("handlers/translations/"))
                {
                    var regex = new Regex("handlers/translations/([A-Za-z0-9-]+)/([A-Za-z0-9-]+).json", RegexOptions.IgnoreCase);
                    var match = regex.Match(url);
                    if (match.Success)
                    {
                        context.RewritePath("~/handlers/translation/getprojecttranslation.ashx" + querystring + "&project=" + match.Groups[1] + "&language=" + match.Groups[2]);
                        return;
                    }
                }
            }