>It sounds to me like you want to clear the 3rd bit. So, BitClear(10,3). But if the 3rd bit(ie - 8) has already been cleared, then you will still have 10. BitClear(2,3) will return 2.

Do I ? <s>

Obviously, there are many values at runtime represented by constants. I need something where I don't actually have to look at the numbers and make decisions about which bit needs clearing. I just wondered if there was a straightforward way I could feed both values in and get the right result.

Thanks anyway!

Best