Matching two groups of data within one sheet

I have two groups of data A21564 and F2:J1417. Each has a column (D & F)
with 10 digit assignment numbers, most of which match from the 1st group to
the 2nd. I need excel to match them keeping the other data in the row from
each group with the assignment #. My second group has less rows of data, so
for some there will be no match. example:
A B C D F
G H I J
11/01/2009 1086 Y 2014927206 2014927206 Z256 80.00 NULL NULL
1/20/2010 3462 Y 2014927740
10/17/2009 2102 Y 2014928543
10/02/2009 2673 Y 2014929240 2014929240 2676 65.00 NULL NULL
10/31/2009 A637 Y 2014929468 2014929468 3739 65.00 NULL NULL
10/31/2009 2224 Y 2014929475 2014929475 2524 80.00 NULL NULL

Also, if there happens to be an assignment # in the F-J group for which
there is no match in the A-D group, I'd like it to stay in sequential order
just leaving the row in the A-D group blank.

I would appreciate any help you could provide. Thanks! Heather