I would just re-create the columns.

1. Copy column A into D.
2. In E1 put:
=IF(COUNTIF(B:B,$A1),$A1,"")
3. Copy it over to F1 and then down as far as needed.
4. Select columns D thru F, copy them, and go to Edit
Paste Special Value. Press OK.
5. Delete column A thru C.

HTH
Jason
Atlanta, GA

-----Original Message-----
Here's my spreadsheet:

A B C

1 1 1
2 3 3
3 4 6
4 5 10
5 8 11
6 9
7 10
8
9
10
11
12
13


How do I get the matching numbers on the same rows, like:

A B C

1 1 1
2
3 3 3
4 4
5 5
6 6
7
8 8
9 9
10 10 10
11 11
12 13
13



.