Random cell/number and dont repeat selected cell/number
 

OK i want a number from 1-43 to be generated at random on cell B1. The random
numbers represent cells A1:A43. Once i get a number, lets say 20. I want to
type the number 20, anywhere on cells C1:E3 or C6:E6. When i type the number
20 in cell D2(or any cell from C1:E3 or C6:E6), i need cell A20 to be
highlighted. Also when i get a new random number 20 can NOT be it. If my next
number is 5, and i place the number 5 on cell C6. Then A5 needs to be
highlighted along with the cell A20 since its still in my C1:E3 box. My new
random number CAN'T be 5 or 20 any more. So basically any number i place in
cells C1:E3 or C6:E6 cant be generated as a random number. If i delete the
number 20 out of D2, then A20 goes back to normal(not highlighed), and it can
be use as a random number again.