凡例を画像ファイルで出力する方法

'Dim pmapdesc As IMapDescriptor = pmapserver.MapDescriptors
Dim pmxdoc As IMxDocument = My.ArcMap.Document
Dim map As IMap = pmxdoc.FocusMap
Dim uid As UID = New UIDClass()
uid.Value = "esriCarto.Legend"
Dim legend As ILegend = CType(map.CreateMapSurround(uid, Nothing), ILegend)
Dim pmapserver As IMxdServer = New MxdServerClass()
'pmapserver.ExportLegend(legend, Nothing, 200, 0, 0, Nothing, "PNG", "C:\temp\Test.png")
pmapserver.ExportLegend(legend, Nothing, 96, 0, 0, Nothing, "bmp", "C:\temp\Test2.bmp")