How to Translate texts contained in MsgBox in Inno Setup?

Question

I have got a [code] section contained within my inno setup script which displays some information for the user during install. I would like to be able to translate these in the

Answer 1

[Languages]
Name: "english"; MessagesFile: "compiler:Default.isl"
Name: "polish"; MessagesFile: "compiler:Languages\Polish.isl"
Name: "german"; MessagesFile: "compiler:Languages\German.isl"

[CustomMessages]
CustomMessage=Undefined //just in case (should be equal to English)
english.CustomMessage=English Selected
german.CustomMessage=German Selected
polish.CustomMessage=Polish Selected

[Code]
function InitializeSetup: Boolean;
begin
  Result := True;  
  MsgBox(ExpandConstant('{cm:CustomMessage}'), mbInformation, MB_OK);
end;