How to create new field while upgrading from CRM 4.0 to 7.0

Hi ,

How do we create new field on UI and store data into existing field in database?

Is there any option in AET to skip the creation of new field in the database table ?

Custom field is already created in GUI and database table while using CRM 4.0

Now, after upgrading to 7.0 EHP3 , I need to bring this field on the UI .

Using AET may create new field again in the database table.Please suggest.

New filed needed to be created in Marketing Campaign Element Header data.

Thanks

Jayasri