The typical way of tracking End-to-End test coverage is to establish a mapping or matrix from requirements, through development tasks and on to testing. For example;
Requirement: Create a login page
-> Task: Develop the login page
-> Test: User can log in
-> Test: User can't log in with invalid credentials
-> Test: User can log in with different personas
-> Test: ...
This is usually handled with a project management or test management solution, for example Jira + Zephyr Enterprise, where the test definitions and outcomes can be compared against requirements and tasks. In itself, TestComplete - like most test automation tools - will be unable to deliver this, but in combination with a management solution TestComplete can contribute information towards a traceability mapping.