Actually, there is no available template to be exported and imported from a central repository to another one.
However, all data and parameters used to define the report(s) (section, description, object .... ) are stored in following tables of central repository:
So you can inject directly content of these tables into other central repository.
Please be careful, as the 'VALUE' column of VIEWER_REPORT_PARAMETERS table contains the snapshot name(s) and the id(s) of selected object(s)
These values should be updated regarding the central contents