What is wrong with this regular expression? here

Question

reg = /^(?=^.{1,200}$)[([a-zA-Z0-9\\\\][-a-zA-Z0-9\\\\]{0,62})|\\*\\\\](\\.[a-zA-Z0-9\\\\][-a-zA-Z0-9\\\\]{0,62})*$/;

the wrong message is Invalid