retention policy behavior in case of fileplan folder and the records inside it

Hi, 

In my requirement I want to create a formal folder in  fileplan and apply retention policy on it such that whenever I am adding records inside it the retention period should start from the creation date of the record in fileplan.

1. Eg. I created one formal folder in file plan folder1 and applied one retention policy on this folder having retention period of 1 year on 1^st May 2012.

I have created a record for some document in folder1 on 1^st May 2012 hence disposition date for this record will be 1^st May 2013.

Now after 1 month I have added one more record in same folder, say on date 13 Jun 2012, then what will be the date of disposition for the 2^nd record?

Is it 13 Jun 2013 or it will be 1^st May 2013?

As per my requirement the disposition date for the record should be 13 Jun 2013.

Also what will happen if the folder is not having any document inside it after 13 Jun 2013?

Is it possible only to associate retention policy with formal folder so that whenever records are added inside folder they should follow the retention policy from their creation date?

Please provide inputs.