The only official ways to access the My Cloud remotely is with the WD Desktop, the MyCloud.com web portal, using FTP/SFTP, and the My Cloud apps for iOS and Android. If you have not already done so you should read the My Cloud User Manual as it explains how to access the My Cloud remotely (see Chapter 8 Accessing Your My Cloud Device Remotely): http://www.wdc.com/wdproducts/library/?id=439&type=25
There used to be a way to map a drive remotely through the Web2Go.com (now MyCloud.com) web portal but WD removed that “feature” when they upgraded to the OS3 firmware. Feel free to voice your complain in the following thread as others have done.
https://community.wd.com/t/re-enable-remote-drive-mapping-through-mycloud-com/134944
