The Cakewalk VST Adapter is an application used to convert VST plug-ins to the Direct X and DX format. This enables you to use all types of available plug-ins with ProTrack. However, Cakewalk VST Adapter might not be compatible with the 2003 version even if you manage to convert all the plug-ins. On the other hand, it appears that Cakewalk VST Adapter is no longer used by users. The official URL is not linking to the page used in the past.