Since the last version of UEM, it is no longer possible to enter user and password. If you write everything in a row you get displayed in the log the error 67
Error 67 trying to map drive 'S:
Is there another possibility user credentials indicate.
This feature is removed for security reasons.
This is also described in the release notes: http://pubs.vmware.com/Release_Notes/en/uem/9.1/uem-91-release-notes.html
If you really need this, you could use a script or maybe GPP?