Combining workbooks from outlook

I had recently read the chapter 13 of the book "M is for data monkey" which refers about "loading data form exchange" and, as I started to think about how can this helps me, I tried some ideas.

One idea that I think it’s going to be very useful at work is:

1) To connect by Power Query (PQ) to my Outlook account (done).
2) To use the PQ interface, filter by the inbox mails for one specific subject. (done)
3) To combine all the workbooks by this specific mail in order to have the information consolidated with the "combining files button" (done) but, here is the problem:

My supervisor wants a weekly report from different regions (north, east, west, south) and, for each region we have one analyst, so, the supervisor sends us an email with an excel which has all the customers (and values) from all regions and the idea is that each analyst fill it up with their comments from the assigned region.

As a result we have 4 workbooks that contains the same information (same columns, same customers) but different comments by region. (To be more clear, "Customer A" appears repeatedly 4 times, once with a new comment filled by the region analyst (which I want), and other three times (with old or null comments, from the other analysts).

The traditional way to work with this is to open an excel workbook with the customers list (with no comments) and fill it up with the comments for each region, this means: open 5 workbooks (one of them to consolidate the information) and copy/paste the comments from workbooks that each analyst.

As I write this the only solution that comes to my mind is to tell them to reply only with the customers they added comments and erase the information form the other regions.

Any other Idea? Does PQ is capable to combine this 4 workbooks and maintain the last information for each area?

Hope I was clear!

Assuming the workbook has a column that identifies a customer's region, couldn't you filter each analyst's workbook for their customers and then append the four workbooks?

As I recall, one of the fields you can extract is the email address of the person who sent it to you. Why not add a table with the email address and the region they are responsible for?

By merging that information against your completed table, you could add a conditional column to check if:

Then filter to remove null.

You might have to tweak it a bit, but hopefully it gets you on the correct path.