Hi Ed,
Here is some example code that you can use to add a nested datatable column
'Declare a new Datatable
Dim dt As DataTable = New DataTable
'Add your Columns
dt.Columns.Add(""ID"", GetType(Integer))
dt.Columns.Add(""Value"", GetType(DataTable))
'Add a row
dt.Rows.Add()
'Assign your output collection
col_Out = dt