Ok, if I understood correctly you have to :
1. List up the available files in a folder of SD card
2. Allow the user to pick files
3. Allow him to specify a folder (to where these selected files have to be copied)
4. Copy them into that folder
You can find answer to point 1 at
http://stackoverflow.com/questions/4895104/file-browser-in-android[
^]
The next two steps involves handling UI events.
The help for last point can derived from the arguments listed at this link
http://stackoverflow.com/questions/5715104/copy-files-from-a-folder-of-sd-card-into-another-folder-of-sd-card[
^]