It is not possible to publish an app that is installed at a network server from the UNC path. So I found at the comments of this TechNet article: http://social.technet.microsoft.com/wiki/contents/articles/10817.publishing-remoteapps-in-windows-server-2012.aspx
That this is possible using PowerShell of course
New-RDRemoteApp -CollectionName [collection_name] -DisplayName [remote_app_display_name] -FilePath "\servershareexecutable.exe"
I modified it because I had some issues with the share. Searching I came up that I first needed to make a shortcut of the executable on the public desktop and then create the app and finally I get it work like this:
New-RDRemoteApp -Alias "alias" -CollectionName "collection name" -DisplayName "display name" -FilePath "C:UsersPublicDesktopapp.lnk" -IconPath "\servershareexecutable.exe"
Pantelis Apostolidis is a Sr. Cloud Solutions Architect professional at Office Line SA and a recognized Microsoft Azure MVP. For the last 15 years, Pantelis has been involved to major cloud projects in Greece and abroad, helping companies to adopt and deploy cloud technologies, driving business value. He is entitled to a lot of Microsoft Expert Certifications, demonstrating his proven experience in delivering high quality solutions. He is an author, blogger and he is acting as a spokesperson for conferences, workshops and webinars. He is also an active member of several communities as a moderator in azureheads.gr and autoexec.gr. Follow him on Twitter @papostolidis.