Use the ICIClientSettings interface SetHomeDirIsRoot method to set a user's home folder as the user's default root folder. Refer to User Account General Settings for an illustration of how this and other Client Settings Interface Methods and Properties can be accessed in the Administrator interface.
Signature:
HRESULT SetHomeDirIsRoot([in] SFTPAdvBool val);
0 = Not default
1 = Is default
-2 = Inherited from User Settings Level