Songbook - Ipad - Loading Files

Hi
I have an Ipad 2 with Songbook, and want to load files from a large number of MSCZ file in a folder in Dropbox.
I am only able to load one file at a time, by highlighting it in Dropbox and the then clicking on the up arrow symbol to allow me to select Songbook to open the file.
Question: Is there a method to load multiple files into Songbook, either via Dropbox or an alternative?
Your comment will be appreciated.