compare two date fields and enter into another. 2 nd request

[TKM]

I have two fields as shown below (break in the data is for the Eample).
Notice in the Effective Date field it has the following dates 06/01/2006 and
07/01/2006 just before the break. I need to be able to move any series of
dates that are different in the Effective Date column just above the next
series of dates. One more catch. the year needs to be changed to match the
other dates in that series. Such as in this case it needs to be chaged from
2006 to 2001.

Start Date Effective Date
05/01/2001 05/01/2006
05/01/2001 06/01/2006
05/01/2001 07/01/2006

07/02/2001 07/02/2001
07/02/2001 07/01/2004

Should look like this when it works correctly
Start Date Effective Date
05/01/2001 05/01/2006
05/01/2001 06/01/2006
05/01/2001 07/01/2006
06/01/2001 06/01/2001
07/01/2001 07/01/2001

07/02/2001 07/02/2001
07/02/2001 07/01/2004

I hope this is not to tough as I am trying to move a series of dates from
one filed to another changing only the year to match. If it checks the
effective date fild against the start field it should trap it. PLEASE HELP!