Well,
it might be a good addition, though the scripted equivalent is so simple, that one might wonder why add it in the first place.
In the mean time, until it gets added, you could try:
Usage: $comchanall(nick)
alias comchanall {
var %a = 1, %b
while $comchan($$1,%a) {
%b = %b $v1
inc %a
}
return %b
}
