I guess it'd depend on their version.

if ($me isop $1) mode $v2 -v $nick($1,%x)

We're checking if we're an op on $1 before we devoice them. In that IF statement $1 is $v2. /autovoice #ChannelHere as you can see $1 would be the channel.

So, for those who aren't using 6.16 mIRC version could use:

if ($me isop $1) mode $1 -v $nick($1,%x)

Edit: Posted and didn't see the reply from when you changed the #ChannelHere.. smile

-Andy