Thanks John, just what I needed.
For future reference, what would I need to do if I wanted to store the
concatenated number in the table.
Well, you almost certainaly would NOT want to do so. Storing derived data such
as this in your table accomplishes three things: it wastes disk space; it
wastes time (almost any calculation will be MUCH faster than a disk fetch);
and most importantly, it risks data corruption. If one of the underlying
fields is subsequently edited, you will have data in your table WHICH IS
WRONG, and no automatic way to detect that fact.
Just redo the calculation whenever you need it, either as a calculated field
in a Query or in the control source of a Form or a Report textbox.
If you did have some good reason to do so (e.g. you want to be able to edit
the concatenation separately from the numbers so that they disagree) you'ld
need to "push" the value into a bound textbox in the AfterUpdate event of the
number controls.