On *:text:!Changeworld *:#: { 
  if  ($nick isop #) && ($2 isnum 2-138) set %world $2 
  if  ($nick isop #) && ($2 isnum 2-138) msg # The world has been changed, type !world to view it 
} 

On *:text:!world*:#: { 
  notice $nick Current World: %world 
}