I am entering project information into a template, which is then saved to a
database. In this template, I use project numbers, and as I open new
projects those numbers get higher.

The following formula references a cell in the template, B19, which is a
description, and then looks in the database for the highest matching project
number that also has that description in its record. Column D is the
description and Column C is the project number. It gives me back a previous
project number that I can use for reference information (the most recent
similar project).

=MAX(IF('[Database.xls]Sheet1'!$D1:$D1000=B19,'[Database.xls]Sheet1'!$C1:$C1
000))

The MAX part gives me the highest match and the IF part makes it look only
for projects that match the description I tell it.

I thought this was the answer to my problem, and it works as I go along in
ascending order, but if I then later open up an old job from the template, it
automatically updates it with new information that isn't valid for the time
that this job is opened. Instead, I need for it to keep the information that
was accurate only at the time I created the project.

This means I need to incorporate into the formula a way for it to tell me
what the MAX is BUT less than than the project's own project number, which is
in cell B4.

CAN THIS BE DONE? Thanks!