9b3eafd4_dio__that_is_the_the_question___SharePoint_Designer_2007
Can create code-behind file(s) that allow you to add any custom code (C#/VB.NET) to your workflow. [SharePoint Designer 2007] 
No code-behind support.
Andrew Connell, MVP SharePoint Server - Authoring workflows in WSS v3 - to use SharePoint Designer or Visual Studio, that is the the question!
SharePoint Designer 2007