Easy... Clr Array[ArrayNum]
Now just set a little counter up and allow the Clr command to run when a LEQ and GEQ are true. GEQ Test A:ArrayNum Test B:5, LEQ Test A:ArrayNum Test B:60, CNT Up element is ArrayNum every scan the counter is uped and that array element is cleared.
If you want to try and clear them in one scan cycle, you might be able to pull it off with a LBL ahead of the CLR rung, and a JMP within the CLR counter rung. this would keep it running through that section until the counter causes the LEQ to go false.