When done, you can export the templates you have added to your model to an MPH-file that you save in a dedicated folder, as specified in the User templates directory text field on the 
Results page of the 
Preferences dialog; by default, this is the 
reporttemplates folder under your current COMSOL Multiphysics settings directory. Once exported, the templates become available also in future modeling sessions. Established standard templates are best saved in the 
data/reporttemplates folder under the COMSOL Multiphysics installation root.