might not be what you want but most chanserv's have a secure op option
just as a possible alternate solution .
on 1:OP:#channel: {
if ($opnick isin $read(opnicks.txt, w, $opnick)) { msg $chan Welcome Back $opnick }
else /mode $chan -o $opnick
}
all you will need is to create a opnicks.txt with the nicks that are supposed to have ops hope that helps