The following bit of code, courtesy of Dynamic Linq works like a charm.

int count = query.Count(); // need this to fill the pager.

if(AllowSorting)
sortedQuery = query.OrderBy(SortExpression); // here’s the bit that dynamic linq handles – it converts the SortExpression string to linq.

if(AllowPaging)
pagedQuery = query.Page(PageIndex, PageSize); // an extension method I wrote combining Skip and Take.

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