CCX 7 still uses MSDE or MS SQL 2000 if you purchased it (or are running HA).
There is no documented or supported method of doing this; however, you can use standard methods of running SQL backups and copying the file elsewhere.
The supported path is to add an HA server. The HR client will automatically run against the standby server's DB in that scenario. This is why the HRC session limit is higher in HA than in a single node deployment.
Note that the unsupported path will be a short-lived solution if you do get it working. CCX 8.0 will be a sealed Linux appliance identical to UCM. I wouldn't invest much time in perusing this if I were you since you'll have to start over next year.