How to copy a file dynamically using inno script?

I'm very new to inno script. I have created a setup file using inno script and I have included one text file in that script. Whenever I run the setup, the text file is copied to destination folder. My problem is that I have to edit the text file before installation. Based on the text file values, I need to configure my setup 开发者_运维百科file. My setup is able to copy the file from source to destination (I'm giving the path manually in the script file) but how to edit the file and how can my setup identify the text file location and how it will copy to destination folder?

I copy the text file to the setup location before doing installation. Now the setup file has to find the location of the .txt file and has to copy to destination.

Anyone know this concept?

Source: "D:\Projects\Sample\Release\Install.exe"; DestDir: "{app}"; Flags: ignoreversion

This is my source file .exe location.

Look at the {src} constant and the external flag on a normal [Files] entry.