使用VBA或VSTO从存储在SharePoint中的Word文档读取/写入人员元数据？

Scenario: Document library in SharePoint with column x of "Person or Group" type. From within a VBA macro (or VSTO add-in) we're trying to access the MetaProperty on the document to set/get the user name. Any attempt to access the value via the ContentTypeProperties collection throws a Scenario: Document library in SharePoint with c