partial-sort

I'm trying to implement a paging algorithm for a dataset sortable via many criteria. Unfortunately, while some of those criteria can be implemented at the database level, some must be done at the app level (we have to integrate with another data source). We have a paging (actually infinite scroll) requirement and are looking for a way to minimize the pain of sorting the entire dataset at the app level with every paging call. What is the best way to do a partial sort, only sorting the part of the list that absolutely needs to be sorted? Is there an equivalent to C++'s std::partial_sort function