MobArena Special Feature Add-On

Original Plugin: http://dev.bukkit.org/bukkit-plugins/mobarena/
MobArena Source: https://github.com/garbagemule/MobArena/

Well to start off, I'm not 100% sure if this would be possible or not. But I'm sure some of y'all developers might take a crack at it. For this request I need a special feature that adds onto MobArena without editing anything of the original plugin.

Plugin category:

Suggested name: MobArena TNT Addon

What I want: For this MobArena addon, I'd like the plugin to be more Dynamic. For the addon I would like to see a feature where you can use the TNT class (Demolition) for a better use. I'd like someone to make it so if you set off a TNT around a specific block will cause the block to break, but ONLY that specific block and any blocks around it that are the same. For instance, say you're in a room, just a basic room with a 2x3 area in the wall made of iron fences. To move out of that room you need to get through the fences. By placing TNT next to the iron fences and setting the tnt off, it will blow up and only destroy the iron bars and no other material around it. Therefore leaving a 2x3 hole in the wall where the iron bars where and leaving everything else in tact. I'd like this either to be set up form the mob arena setup, or just a general feature from the custom plugin that allows this to happen either world specific or Mob Arena arena specific. If you can find another way let me know.(=

Ideas for commands: No commands.

Ideas for permissions: No Permissions.

When I'd like it by: Not picky in the slightest, whenever you can get it done is fine. (=

Thank you for anyone willing to take this challenge on! If anyone knows a way to do this already without the need for a custom plugin please inform me, I'd greatly appreciate it! Thank you! (=