Code:
class Window_MapName < Window_Base
  def refresh
    contents.clear
    unless $game_map.display_name.empty?
      tmap_name = $game_map.display_name
      while tmap_name =~ /\\V\[(\d*)]/
        tmap_name[/\\V\[(\d*)]/] = $game_variables[$1.to_i].to_s
      end
      draw_background(contents.rect)
      draw_text(contents.rect, tmap_name, 1)
    end
  end
end
Edit: Gepanks war schneller