Help USB file access through program

[USB file access]

Hi,

I am Raghava, working as Android application developer.
I would like to know the solution for accessing files in USB and do file operations like copy, delete ...
When I use Android APIs for External Storage, it is leading to only SD card, not to the USB device.
Appreciate your help.
Please let me know if you need any more details.

Thanks and Regards
Raghav