Injecting code to track events on Delphi

I have a big and old application written in Delphi version 2007 for over a decade now and in order to rewrite it I intend to understand which parts/features of it are mostly used by the majority of its users.

The idea that came up is to track objects clicks and window creations to populate a log or analytics tool like Google Analytics or Deskmetrics with quantitative and qualitative data in order to help on the decision making.

To achieve that, I'm trying to figure out what is the easiest path respecting the current version limitations. One of the possibilities I am exploring is understanding how to implement some generic code that could be somehow "injected/reflected" in a class level so all instantiated objects may among other things, call a function passing parameters that identify themselves and this function would then take action to log that info using the best tool.

The only real solution so far is copying and pasting this function call on several thousands of onClick/onCreate methods and I'd like to avoid it while I am open to all other possibilities that may come out on this thread.

Thanks!