I've not use hOS.dll, but by the looks of it, you can do it like this:
on *:nick: {
if ($nick == $me) {
//dll hOS.dll AddStatusBar | //dll hOS.dll SBSetData 1 +n 1 $chr(160) Nickname: $me
}
}
Note that this is not a mult-server thing... if your nick isn't the same on each server, you'll have to do more scripting to make it change when you change from server to server.