Something

alias leave {
  set %away.time $time(hh:nntt)
  set %orignick $me
  nick $me $+ |away
  set %away.reason $1-
  amsg i am now Away at: %away.time | Reason: $1- 
  away %away.reason
}

alias return {
  nick %orignick
  amsg i am now back at: $time(hh:nntt) | From: %away.reason
  unset %orignick 
  away
}