page with variable at the header

Hi, guys!
I am trying to create kind of a master page for making some new entries.
Take a look at the screenshot attached.
The idea is we have some fields which are variables at the top of a page
eg PostingDate, BankAccount, does not matter
(which will be used to create new entries)
and repeater with entries we want to correct.

The user defines fields for new entries and selects existing entries which he wants to correct.
Then he pushes Action "Go" and voila - all is done.
Haha, not at all.

I am stuck with the fields at the header!
For example, I define BankAccount field (it is variable!) then I want to select some entry and after i moved from one line to another BankAccount changes to empty value! If I go back to previous entry BankAccount again has the value I defined.
How to avoid it? How to "exclude" variables on the page from the dataset?
How to make it simple independent variable?

Thanks...