Unable to update nickname of a folder created with Case Template using webserive DocumentManagement.

I created a folder using RESP API /doctemplates/{id}/instances with Case Template. I need to change the folder's nickname to a certain format. Since REST API doesn't have anything for updating nickname, I use webserive DocumentManagement.UpdateNode to update the folder's nickname, but it fails due to exception "Update of specified node type is not supported.". I am able to update the nickname of a binder using UpdateNode though. Can somebody help me with this please? BTW, our CS is 10.5.