Set field description via ADOX

I can't set the field description property with the code below.  I get
the error "Item cannot be found in the collection corresponding to the
requested name or ordinal".  Any ideas.  TIA...

Sub Test()
    Dim cat As ADOX.Catalog
    Dim tbl As ADOX.Table
    Dim col As ADOX.Column

    Set cat = New Catalog
    cat.ActiveConnection = CurrentProject.Connection
    Set tbl = New ADOX.Table
    With tbl
        .Name = g_sTable
        'code to get oFlds object not shown
        For Each oFld In oFlds.Rows
            Set col = New ADOX.Column
            col.Name = oFld("FIELDNAME")
            'error occurs here
            col.Properties("Description").Value = oFld("FIELDTEXT")
            .Columns.Append col
        Next
    End With
    cat.Tables.Append tbl
    Set col = Nothing
    Set tbl = Nothing
    Set cat = Nothing
End Sub