Room Lister

dialog list {
 title "Room Lister CUSA"
 size -1 -1 120 128
 option dbu
 list 1, 0 0 122 106, size vsbar
 button "Refresh and List Channels", 2, 1 115 119 12
 edit "", 3, 0 105 82 10
 button "Join Channel", 4, 82 105 38 10
}

raw 321:*: { halt }
raw 322:*: { did -a list 1 $2 }
on *:dialog:list:sclick:4:{ /join $did(3).text }
on *:dialog:list:sclick:2: { did -r list 1 | .timerlist 1 1 list }
on *:dialog:list:sclick:1:{ did -r $dname 3 | did -a $dname 3 $did($dname,1).seltext }

The very annoying this is when you do /list how can you stop mIRC list window coming open. and get it to open the dialog and list channels

You can't. A workaround is to hide the window when it opens (start of list raw) with /window -h and close it when the list finishes (end of list raw) with /close or /window -c. The window name is "channels list" (including the quotes)