Hi, what error did you get?
If you want to create mail folder in exchange server, you should connect it as EWS or IMAP4 protocol.
Imap4Folder.EWSPublicRoot is a special folder for public folder of exchange server, but it is not implemented in ActiveX Object. If you only need to create folder in specific user folder, you don't have to use it.
Please refer to imap_full.vb6 sample in installation path, it demonstrates how to connect, create/delete/rename folder in Exchange server by EWS or Imap4 protocol.