怎样通过SDE的图层获取到对应的Imetadata?

一般是用arccatalog的VBA程序来获取IGxObject，Set pMetadata = pGxObject就可以实现。但我想用独立VB工程，目前连接到SDE数据库，可以获取到featureclass，怎么能获得这个Imetadata这个接口呢？arccatalog的VBA程序：

Sub ExportMetaDataFromPath(sInPath As String, sOutPath As String)

Dim pApp As IGxApplication
Set pApp = Application

Dim pCatalog As IGxCatalog
Set pCatalog = pApp.Catalog

Dim pGxObject As IGxObject
Dim numFound As Long
Dim v As Variant
Set pGxObject = pApp.SelectedObject
Dim pMetadata As IMetadata
Set pMetadata = pGxObject

If Not pGxObject Is Nothing Then
   
   Dim pMetadata As IMetadata
   Set pMetadata = pGxObject
   
   Dim pExportHTML As ExportHTML
   Set pExportHTML = New ExportHTML
   Dim pExportMPHTML As ExportMPHTML
   Set pExportMPHTML = New ExportMPHTML
   
   Dim pExport As IMetadataExport
   Set pExport = pExportMPHTML
   
   pExport.Export pMetadata, sOutPath ; "\" ; pGxObject.Name ; ".html"

End If

End Sub