Minecraft Redstone Help

I need help with a map, I'm wondering if there's a command to make a lever or a button to trigger a command block without the command block being behind the button or any redstone near the button.

The best option is to have a repeating command block that is always active (or active when you want it to be) constantly checking for a pressed button, or in this case, a stone button with a certain damage value. That command block will lead into a conditional command block that will perform whatever action you want.

/testforblock ~x ~y ~z minecraft:stone_button [damage value]
 |
 | conditional
 |
 V
/tellraw @a {"text":"Successful"}

The [damage value] will change depending upon the direction of the button:

East: 9

West: 10

South: 11

North: 12

Play around with the command a bit and you should get it working ;)

source: www.minecraftforum.net