How to mask a file in SFTP adapter

Hi Everyone,

       We are using SFTP asa  sender adapter.In the sender side,we have to pick the different files from one folder.How is it possible using SFTP.

I have checked the links but they mentiond the file names starts with the same name.

Example:

Folder name:   ABCD

File names : Dummy1.txt

                   Hello2.txt

                   Fine31.txt.

Can anyone throw some light on this ??