.htaccess - Block direct access to port which is using app -

i running app on port 799. prevent people accessing via direct access:

http://www.website.com:799/folder/1 

however, need port still listen , operate otherwise. example, pages direct user to

http://www.website.com:799/folder/1  

after checking see whether members. link never revealed url user. there anyway specify via htaccess block contents when user has requested directly via url otherwise let contents show. (when requested via php).