Logic Hooks

In the calls module, we have logic_hooks file and I have to implement before_save hooks in calls module but that file is auto-generated and I cant edit that file.
Is there any other way to create another logic hook file.

/custom/modules/calls is the path where I want to create a before_save hook.

You can refer to the answer here: https://community.sugarcrm.com/thread/23754 on how to create a custom hook

On SuiteCRM Developer Guide: https://docs.suitecrm.com/developer/logic-hooks/

And on SugarCRM 6.5 Developer Guide: http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_6.5/Module_Framework/Logic_Hooks/Module_Hooks/before_save/