/setup/ui/recordtypeselect.jsp?ent=Case&retURL=/500/o&save_new_url=/500/e?fromAccountId={!Account.Id}&retURL=%2F500%2Fo

<https://myorg.cs6.force.com/**CommunityName**/setup/ui/recordtypeselect.jsp?ent=Case&retURL=%2F**CommunityName**%2F500%2Fo&save_new_url=%2F**CommunityName**%2F500%2Fe%3FretURL%3D%252F**CommunityName**%252F500%252Fo>