Well mirc has the option to keep the channels open when disconnect in options, but will not keep the nicks listed in the listbox since your not connected, which makes sence! What you need is to script something that works for you maybe by using the on :disconnect: event.
A quick example for #mirc I used /filter to filter all the nicks from the channel into a .txt file, you could then either open this text file or just filter it to your own @window!
on *:disconnect:filter -cwfl #mirc mircchan.txt | run mircchan.txt
The ^ event prefix currently works only on the following types of events: ACTION, BAN, CHAT, DEHELP, DEOP, DEVOICE, HELP, INVITE, JOIN, KICK, MODE, NICK, NOTICE, OP, OPEN, PART, PING, TEXT, UNBAN, USERMODE, VOICE, QUIT, SERV, SERVERMODE, SNOTICE, TOPIC, WALLOPS.
He he How i can stop the mIRC to disconnect ? I mean .. Stop display ?
The point here was to still be able to see the nicklist in open channels when you disconect... witch is not possible... You scripting line dosn't stop this... I'm pretty sure there is absolutely NO way to stop this... maybe would be nice to suggest to Khaled to re-add it