Add Files to the files datatype manuall

Hi,

i have the following question:

I would like to add a file to the file selection manually like i can do with other values, something like this:

editor.val( 'name', 'Testname' ]);

editor.val( 'files[].id', [{'id':'newFile.jpg'}]);

Means: I would like to add the picture via API like i would have choosen the "choose file" button.

Questions: What´s the correct format for the JSON ?

I have tried a lot but can´t get it to work

Does anybody have an idea ?

Thanks and Kind Regards, Christoph