For a relative file path like "\abc\def\file.txt" I need to check if the file is located in the "\abc\def" folder (or in any of its sub folders). Let's call this "\abc\def" a predefined path. Note that I am not interested in the drive nor the path complexity before "\abc\def".
A simple understanding of Delphi is fine when you create applications for home use. Once you start building real-world applications you'll start looking for ways to solve more complex tasks - and Delphi will have all the answers!