I'm new here and somewhat confused. I'd like to create a skin for the windows clock in the system tray so that I can control the appearance of the time, tooltips, window that pops up when double clicked, etc. There are lots of programs that do this and it all seems very mysterious.

How does one go about doing this? The MSDN entries on skins were confusing. Some websites talk about patching system dll's, or requiring digital signatures. Are there Win32 API calls that need to be made? Help!