Access 2000 Question

I need to add a list box to a form with the multi select option set to on. This is not a problem.
My question is :
-I already have a table that contains the values I want to be listed in the list box and know how to have the list box look up thesevalues
-On my main table, how do I have the selections made in the list box show up? Is it possible to have the multiple items selected in the list box show up in one field on the main table?
-Do I need to create a many to many relationship?