The solution you gave removes the moved piece instead of the piece at the to-location.. (and there was a missing close-bracket, which I added in the attached .lud).
Edit: Sorry, my brainfart. I wasn't able to apply this to my project, but it works fine here. I got confused.
Edit: Sorry, my brainfart. I wasn't able to apply this to my project, but it works fine here. I got confused.