[AccessD] Heck of an Access Question

Ok.  I have a doozy of a problem this time.  My
Marketing department has tasked me with creating a
database/questionnaire for our customers.

In the data that I am going to be given, each customer
has a specific customer number, however, based upon
how many items that they purchased on their most
recent invoice, they might be in the table multiple
times.  If they purchased one item, they're in one
time.  Two items, two times.  Et al.

My problem is this.  I need to "convert" these
multiple entries into a single entry concatinating all
of the non-matching data.  Such as items purchased. 
Obviously, their customer info should be the same.

Any assistance that you can give me would be greatly
appreciated.  Thank you.