We have done something Similar and had to use Search and Navigation to Find the Page to serve full example here 

    public class CampaignRouter : IPartialRouter<InsightLandingPage, CampaignPage>
    {

#if DEBUG
        private readonly TimeSpan _cacheTimespan = new TimeSpan(0, 0, 0);
#else
        private readonly TimeSpan _cacheTimespan = new TimeSpan(0, 30, 0);
#endif
        private ContentReference _container;

        private string _urlSegment;

        public CampaignRouter()
        {
            var settings = ServiceLocator.Current.GetInstance<ISiteSettingsProvider>();
            _container = settings.Current.InsightsContainer;
        }

        public object RoutePartial(InsightLandingPage content, SegmentContext segmentContext)
        {
            if (!content.ContentLink.CompareToIgnoreWorkID(_container))
            {
                return null;
            }

            var nextSegment = segmentContext.GetNextValue(segmentContext.RemainingPath);
            var urlSegment = nextSegment.Next;
            if (string.IsNullOrEmpty(urlSegment))
            {
                return null;
            }

            ArticleBasePage article = null;

            var cacheKey = $"routing-insights-{urlSegment}";

            var cache = ServiceLocator.Current.GetInstance<ICache<ArticleBasePage>>();

            _urlSegment = urlSegment;

            if (cache.IsExists(cacheKey))
            {
                article = cache.Get(cacheKey, GetArticleBasePage);
            }
            else
            {
                article = GetArticleBasePage();
                if (article != null) cache.AddToCache(cacheKey, article, _cacheTimespan);
            }

            if (article != null)
            {
                segmentContext.RemainingPath = nextSegment.Remaining;
                segmentContext.RoutedContentLink = article.ContentLink;
            }

            return article;
        }

        private ArticleBasePage GetArticleBasePage()
        {
            var urlSegment = _urlSegment;

            ArticleBasePage article = null;

            var searchContext = SearchClient.Instance
                .Search<ArticleBasePage>(SearchClient.Instance.Settings.Languages.GetSupportedLanguage("en"))
                .Filter(x => x.URLSegment.MatchCaseInsensitive(urlSegment))
                .Filter(d => d.Ancestors().Match(_container.ID.ToString()))
                .StaticallyCacheFor(this._cacheTimespan)
                .Select(r => r.ContentLink);


            var searchResults = searchContext.GetResult().FirstOrDefault();

            if (!ContentReference.IsNullOrEmpty(searchResults))
            {
                var contentRepository = ServiceLocator.Current.GetInstance<IContentRepository>();
                article = contentRepository.Get<ArticleBasePage>(searchResults);
            }

            return article;
        }

        public PartialRouteData GetPartialVirtualPath(
        CampaignPage content,
        string language,
        RouteValueDictionary routeValues,
        RequestContext requestContext)
        {
            var contentLink = requestContext.GetRouteValue("node", routeValues)
                as ContentReference;

            if (!content.ContentLink.CompareToIgnoreWorkID(contentLink))
            {
                return null;
            }

            if (PageEditing.PageIsInEditMode)
            {
                return null;
            }


            return new PartialRouteData
            {
                BasePathRoot = _container,
                PartialVirtualPath = content.URLSegment
            };
        }
    }