Control the telnet

In my system , all user login are via telnet , we have control that only allow max. 300
telnet session in the system , now if I want to keep the max. no of telnet unchange (300) ,
but three specific users ( eg. userA , userB ,userC ) not count into this 300 session , is
it possible ?

for example ,

there are 300 user are in the system currently , if userA , userB & userC are also in the
system , the general user can still login until the no. of telnet reach to 303 ( as these
three users not count into the 300 , in short , the login of these specific users are
separate from general user ,

I really need help on that , but not sure whether I have mention about it , please let me
if not clear , thx in advance.