detect structure?

[cheatchki]

Is there a way to detect a structure, I would like to make a "portal" that players can make that works similar to the nether portal, however I'm just not sure on how to even start this. I don't need all the code but could someone give me like a small amount of code to detect
1. if a block is placed like a magma cube itll detect if a diamond block is 2 blocks above it, if so itll do something? that will give me the start and i can do the rest
2. then im thinking the smartest way to get the player to teleport is to create an invisible mob with a special hidden name inside the portal, then if the player touches the mob itll teleport them to the corresponding mob in another portal but if you guys think there is a better solution like setting a variable to a block location and if a player touches that then itll tele them or anything else please post your opinion

 

[Deleted member 5254]

I think the easiest way to do this would to be sort of like nether portals where you have to right click an item to "activate it" at that point you could loop the blocks in a radius and check for specifics. You could do the teleport in that portion too if it all tests true maybe. Really prefer to do teleportation and custom portals with worldguard myself so I can trigger it off a region enter