Getting a Source Table using ADO

I cannot get the source table from an ADO field object in Matlab. Here's a quickie code explanation:

>> dbconn = actxserver('ADODB.connection');

>> dbconn.Open(connString);

>> rs = dbconn.Execute(sql);

>> fld = rs.Field.Item(0);

>> prop = fld.Properties('BASETABLENAME');

>> prop.Value

>> prop.Type

ans = NaN

ans = 'adVarWChar'

regardless of the type of query or field I grab, the BASETABLENAME and BASECOLUMNNAME properties always com out to be NaN's. I'm using Matlab 2010b. My hunch is that Matlab is unable to convert adVarWChar to a char, but not posisitive on this. My source issue is obtaining the source table of any given field in a recordset. Any help is appreciated.