In order to connect to a remote Windows server via CIFS using a different user account, enter the following command in a Command Prompt (CMD) window:
net use \\<servername>\IPC$ /user:<netbiosdomain>\<username> *
This will authenticate the supplied user to the remote server, ensuring that future CIFS connections use the authenticate user account.
Note that if existing connections have been made with another user account, they will need to be removed first. You can display a list of connections using net use. Connections can be removed using net use \\<servername>\<sharename> /delete
One this command has completed successfully, open a Windows Explorer window and connect to the desired path as per normal.