Returns the name of an attachment.
AFTKN_ITEM_ATTACHMENT_NAME or 669
ANSISTRING ItemAttachmentGetName(ANSISTRING MessageID; WORD Index)
Unique item identifier, returned by ItemMessageIDFromView().
Attachment index number (zero-based).
ANSISTRING. Attachment name.
IMPORTANT:Return is based on a difference in attachment class type. An attachment of class type "Message" will be its MessageID; an attachment of class type "Embedded OLE object" currently returns an error; and, an attachment of class type "File" is path\displayname (if using X00 for the msgID or just DisplayName if using the actual MsgID).