I need to be able to detect exactly which unit cast it, anyway. So... after more work, my porblem was mutated.

I now need to know if it's possible to hide the build button. I tried covering it with a spell, but the spell was just pushed off to the side. Might I be able to move it to -1, -1, or 4, 1 or under the move button somehow?
Thanks for all the help so far!
Edit: After some tinkering, I've been able to change what it says on the build button(by editing CommandStrings.txt), but not it's location(by editing CommandFunc.txt).