A cell with a formula that i want to keep but reset the cell value to zero with a macro

I have a cell that has a number in it and i want to reset it back to zero without it clearing the formula.
Im trying to have a raffle of 6 numbers without any duplicates which i can do but but i want to reset it back to zero so that when I use it next time it shows a zero before clicking a button to give 6 different numbers the next time i use it.
Hopefully that is enough info for ypu.
Andrew