How to access extSdCard from unity3D

Hi Friends,

My English is not good....

In my app i want access sdcard and extSdCard both.

for sdcard
"/mnt/sdcard/ + "MyFile.txt";
its working fine.
but for extSdCard
"/storege/extSdCard/ + "MyFile.txt";

this code is not working by unity3d
by eclipse this code is working
if anybody has idea pls help me here...