The administrator should use \server%username% to correctly map a script to a home directory for a user based on username. %username% is an environment variable that represents the current user's name on a Windows system. By using this variable in the path of the script, the administrator can dynamically map the script to the user's home directory on the server. For example, if the user's name is John, the script will be mapped to \server\John.
Reference:
https://social.technet.microsoft.com/Forums/windows/en-US/07cfcb73-796d-48aa-96a9-08280a1ef25a/ mapping-home-directory-with-username-variable?forum=w7itprogeneral