Combing Multiple Columns For Sorting With Generic Member Expressions

I've followed examples here and here to create a generic sort with memberexpressions, but how I'm supposed to add a "ThenBy" clause, or combine multiple columns for sorting in the methodcallexpression. Ideally, the ThenBy should go before skip, but it can't because it can't see the orderby clause that I made with the methodcallexpression. GridSortExpression is a Telerik class - it just describes which column and direction the query should be sorted.

Here is what I have right now:
Dim exp As Expressions.Expression(Of Func(Of Product_Catalog, Boolean)) = PredicateBuilder.True(Of Product_Catalog)()
exp = exp.And(Function(e) e.Chapter_Price > 30)
Dim sortExpression As New List(Of GridSortExpression)({New GridSortExpression() With {.SortOrder = GridSortOrder.Descending, .FieldName = "Id"}})
[Code] .....