I don't have a copy of Access, so I can't see your example, so forgive me if these questions seem stupid.

It sounds like you've got a table that looks like this:

1:A
1:B
1:C
2:D
2:E
3:F
3:G
3:H

and you want to find all the letters that match a particular number, right?

So you just want to know how to construct a query that will give you back a result that shows all of the letters for each number. Basically, in pseudo code:
Code:

---

array = select unique number from table
for each array_element
  select * from table where number = array_element

---

Or are you wanting a new table that will combine all of the letters into a single field so that the numbers become unique?