Thanks again to John, Jason and Flame Retired......all formula are useful if the markers are 'text'. In reply to John's query -- there is no reason why the markers are text as "1" etc, and my formula works equally well with either a number or text. Jasons/Johns adaptation only works with text markers. Could your formula work with numbers? How can one modify them. Flame Retired array formula is also OK with Text but I haven't been able to modify it for 'numbers'. As far as the second message from FlameRetired -- it isn'ty possible to add a column at 'O'.

Cheers -- appreciate all of the communication

Chris