function CustomMessage(const MsgName: String): String;
Returns the value of the [CustomMessages] entry with the specified name. If an entry with the specified name does not exist, an exception will be raised.
var S: String; begin S := CustomMessage('CreateDesktopIcon'); // S = 'Create a &desktop icon' S := FmtMessage(CustomMessage('UninstallProgram'), ['My Program']); // S = 'Uninstall My Program' end;