did you try following way??
alias F5 {
set %test.dia $readini(mirc.ini.mirc,email)
dialog -amv dialog.test dialog.test
}
or
on *:dialog:dialog.test:init:0: {
did -o $dname 665 1 $readini(mirc.ini,mirc,email)
}
or after opening dialog
do //did -o dialog.test 665 1 $readini(mirc.ini,mirc,email)