Concatenate text strings from column using multiple criteria condition (formula)

Hi!

I am looking for a way of creating the following conditioned concatenation, and was looking for help here.

I have two tables, let's call them "summary" and "detailed".

The "detailed" table is something like the following:

ID	VOL
001	01
001	05
002	04
002	01
001	03
003	06

The "summary" table below gets info from the "detailed" table. The 'ID'is now unique. I'm looking for a formula on the 'VOL (concatenated)' column cells it should get all rows from the "detailed" table with the same ID and then concatenate the 'VOL' column results, comma separated:

ID (unique)	VOL (concatenated)
001	V01, V03, V05
002	V01, V04
003	V06

Thanks very much in advance for your help.

PS: I have people using this table with office 2003, so compatibility is necessary... :S

(edit) PS2: this probably should be place on the formulas subforum, sorry about that. :S

Look at the attached. It has a UDF that will do this for you.