Rename cell based on duplicate compound key

[luckycharms]

Hi Folks,

I'm trying to rename a cell when there are duplicates of mutliple columns. Here's an example

Col_1   Col_2   Col_3   Note
A1      B1      C1      
A1      B2      C1      Not a Dup
A1      B1      C2      Not a Dup
A2      B2      C2      
A2      B2      C2      Duplicate
A3      B3      C3      
A3      B3      C3      Duplicate
A3      B3      C3      Duplicate

I would like the query or code to update Col_3 (or add another column if that's easier) as below. Note that the order of the duplication is important.

Col_1   Col_2   Col_3   Note
A1      B1      C1      
A1      B2      C1      Not a Dup
A1      B1      C2      Not a Dup
A2      B2      C2      
A2      B2      C2Dup1  Duplicate
A3      B3      C3      
A3      B3      C3Dup1  Duplicate
A3      B3      C3Dup2  Duplicate

I've seen solutions that use row_number() and over() clauses, but those just work in sql server. Any thoughts for how to tackle this in Access?

Thanks!

[June7]

You need to calculate a value for a record based on value in another record. Requires subquery or VBA code.

Review http://allenbrowne.com/subquery-01.html