Analyze in Excel

yes, it is possible, but I am not entirely sure about your setup.

• You have a table in Excel with data coming from another source
• Add the column "Comments"
• Now select a cell in the Table and do Left-Click|Get Data from Table/Range
• This produces a new query including a column for the comments
• Go to your original query and use a Merge join to add the Comments
  You will need something to uniquely identify a row in your table here!
• Refresh your Excel table
• It will now have a column "Comments" and a columns "Comments2
• Delete "Comments" and rename "Comments2" to "Comments"
• From now on, each refresh will get the comments entered by the user, add them to your analysis results and use them to repopulate the Comments column, making it appear like the comments were not changed.

I have been using this type of construction in a couple of cases and it is fairly stable and robust.
Only adding and removing columns requires some care...