Automatic name for PDF when doing "Save as"

Hello everyone, 

I am very new at using Adobe Acrobat and I would need a bit of help for something I'd like to implement.

I created a basic form to be filled by different people, at different time. In order to differenciate each form with a number, I created a field that generate a number constantly growing (thanks to new date().get time() ).

Now that this is done, I would like to add a simple feature which would offer a new name to the PDF when the user save it after fulfilling it. 

To be perfectly clear, this is the scheme:

- I fulfill the form

- I want to Save it as a new document on my computer

- I click on "Save As..." in the menu

- At this point I select the destination of the forms

- One I have choosen the destination, I need to enter a name. I would like the name proposal to be automatically linked to the number generated in the PDF. I would like to create something like: 

Save As ("Carte cadeau -" & this.getField.data)

Does anyone knows how to implement such a thing?

Thank you very much in advance!