Solved Custom launcher for old version? (unsupported)

Hi, first of all sorry for my English, I'm Brazilian.
I need help, I'm having a server project in version 1806 for people with a weaker computer, and I was wondering if there is any way to create a launcher where people would only be able to get through the server through it, so I can add an anthack, can anyone help me?

 

I can, pm me in discord rustyvaultboy#2562