If you wish to configure your XenApp environment to be accessible via the same URL, both internal or external, then be aware that this isn't as simple as it used to be with Web interface. Web interface was in no way comparable to the enhanced security and architecture of the modern Citrix Storefront and Netscaler Access Gateway.
To configure the same URL for both internal and external users, you will likely need a SAN certificate with the CN name configured for your external domain, plus the internal Load Balanced store DNS address and Callback address.
It is possible to configure the Receiver client to use Beacons and identify whether they should authenticate via an internal or external URL. Think carefully with regards to single URL, as it may not be required. I'm not a fan of placing the internal storefront name on a Public Certificate. Do your users really care whether they have to type in "Storefront" into their web browser when working on site? It is also very easy to just place the external url on a corporate internet page as a link, or add the link as a shortcut to the Desktop or Browser favourites.
Do you really need a single URL? Probably not.
