how to find a most recent file in a path

Hi Guys,

     I am creating dynamic files in a path. So the file name is like ABC20150626.csv.Now in the next step I am using a wait for file() command.Now the problem I am facing is when I am doing wait for file ('ABC*.csv ) it is selecting all the files not the most recent files ( which is greater than zero size ,as I have also given a check on that) and later does the encryption as per business need.

    Now I need your help on this -I mean here how to search for the most recent file in the path.

Problem is I don't have access to this output path. So I am not able to use a global variable.

Thanks

Deb