Replacing Minecraft block objects (and such)

I’m not exactly sure where to post this as the problem is very specific to certain things.

I’m sure everyone is familiar with the game Minecraft and how you can import Minecraft worlds into blender (for use with “Machinimas” and things that cannot be achieved in the actual game). However, most importing tools cannot import “special” blocks such as torches and fences, so, they are replaced with flat planes or some other representation of the object. You will need to replace these objects somehow. Placing them by hand is a terrible way of solving the issue when you have a big area. So how can you replace them automatically? This also goes for things like replacing the leaves on trees and such.

I need more information, but have a look at: Object Data (wehre e.g. the vertex groups are), first option on the top is a dropdown. You can exchange the mesh, the pos / rot / scale remain the same.

Well… the block import tool exports every block type as one mesh. So all of the dirt would be one mesh, and all of the stone will be another. I assume doing what you suggested would just make all of the desired object to replace one, solid mesh like a monkey head.