Oracle Form : navigational problem in data block

Overview of the problem
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We are in environment where we have codes and tables from an existing third party company.
We are allowed to modify coding(opensource);
However, we are very reluctant to change baseline tables.
Consequently, we have chosen to create reference tables if we need additional fields.
Essentially, these reference table have the same keys than the baseline tables.


Problem definition:
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The form related to employee info, had 3 components:
Header block(capturing employee no)
Data block 1 (table 1 with emp_no as Primary key with other fields)
Data block 2 (table 2 with emp_no as Primary key with other fields)

I created a new block called
Data block 3(table 3 with emp_no as Primary key)
This table (NOT baseline) contains my new field.
If it was possible, I would have added this new field to data block 1(table 1).
My new field is displayed in the same group of data than data block 1.

I created a relation(master-detail) between baseline table 1 and my new table 3; because I want to take advantage of the cascading delete. It a one to one relation between table 1 and table 3.
If I delete one employee in table 1 , it will be done for table 3.
If I insert one employee in table 1 , it will be done for table 3.

With this design I am not able to give to the user the feeling that the field in data block 3 is an extra field of data block 1.

When the user use NEXT BLOCK function, the navigation is very confusing for the user.


Is there a better way to proceed???

Thank you in advance!