Code:
scon -a echo -a $!server

The scon -a means to do the command in all connections.
Using $! makes mirc process $server on each connection instead of processing it immediately and echoing that server as if all of the servers had that name.
So, this would send a message to all servers saying Hello from the server you sent the command from.
Code:
scon -a amsg Hello from everyone on $server.

And this one would say Hello to everyone on $server but the server name will be the server the message is being sent to and not the server the command was sent from.
Code:
scon -a amsg Hello to everyone on $!server.

Hope this is what you needed.

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