The best way would be to have a table to store the date, identifying linking
data (ProjectID), and the actual comment. The way you have this set up, you are
going to have to write some vba code to start at the end of the comment and move
back thru the data until it finds a date (or other delimiter) to identify the
start of the last comment.  Once it has done that, it can return the last comment.

If I have misunderstood your structure, then post back with the relevant parts
of the table structure and perhaps someone can help you build a query.