>The seemingly simple things allude me. How do you reference multiple selections from a listbox for use as variables in building an expression that will filter a free table? The listbox has only one column, taken from a field in the same free table.

David gave you right idea. It's just an extension:

CREATE CURSOR tmp (myfield C(10))
For n=1 to Thisform.MyListbox.Listcount
 If Thisform.MyListbox.Selected(n)=.T.
  Insert Into tmp Values(Thisform.MyListbox.List(n))
 Endif
Endfor
Select ... From Mytable Where Myfield IN (Select MyField From tmp)