CustomMessage

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('NameAndVersion'), ['My Program', '1.0']);
  // S = 'My Program version 1.0'
end;