Sorry, that's my fault the dates in red should have been 01/05/20199,01/06/2019,01/07/2019 but for some reason I missed that I'd put those dates in like that.

The thing is, there could be 20 sites where their numbers have changed and they could have changed after the 1st meeting, the 2nd or the 3rd etc, so there wouldn't be a way of knowing for each site (of which there are almost a 1000 in real life) at what stage they changed and therefore, which column relates to the old vs new site number for all sites i.e, there's no hard and fast rule to say Column D will always = the old site and E onwards will always = the new site. So column G for example may relate to the old site number for some sites and for others, who have never had a site number change, it would only relate to the current site numbers.

Hence the need for something dynnamic so that, each month when I put the raw data into the "Raw data" tab it quickly populates data into the report (for context, I would know from a seperate summary report I receive when sites have changed numbers and what the new site number is, and I manually update the site numbers ready for when we get the raw data)