I recently saw a tutorial on how to make an easy programmable keypad. In this tutorial, the author was using it as an easy way to access PhotoShop shortcuts easily. Using a program called HID Macros, you can just make a key on the keyboard input different keys. You can just buy an external USB number pad, and change the keys to do different shortcuts, like pressing 6 on the pad will do Ctrl + Z. Another great feature of HID Macros is that it doesn't just check when you press a number, it also checks what device you are pressing it on. So pressing 't' on your laptop keyboard and 't' on a USB keyboard will be seen as two totally different keys.
Then, you can paste icons onto an external number pad, so it is easier to see. Here is what that would look like for PhotoShop shortcuts:
Then, I had the idea to use this for Minecraft, and put the controls there. I ordered an external number pad similar to the one above (without those icons, of course), which is going to come in tomorrow. Meanwhile, I tried doing simple test on an external USB keyboard that I wasn't using, and it works pretty well. Here is what that looks like (ignore my horrible drawing skills and low quality):