Hello,
Not sure I understand the question correctly, but I will assume that by "Anki does NOT reorder cards based on the results of a custom study session" you mean that cards are not rescheduled according to the answer you provided (i.e., whether you remembered the card correctly or not).
If that's the case, it is possible to use filtered decks to not update the scheduling information (e.g., for cramming as many cards as possible before an exam). But it is also possible to create a filtered deck that updates the scheduling information (e.g., for focusing on a subset of cards).
See the manual for details:
and look at the "reschedule cards based on my answers" option.
Later in your message you talk about "new" cards. In Anki's parlance new cards are cards that have not been learned before. The order of new cards is controlled by a setting and it can be configured as the order in which they have been created. If your cards were created in order 001..100 and you choose to see new cards in creation order, they this will work as expected (no new cards in the 051-100 range will be shown before all cards in the 001-050 has been seen at least once).
Finally, you can use two different filtered decks for new and old cards, so that old cards will be shown from any deck in the order in which SRS will show them, while new cards will be picked from a specific subdeck, so that you always know from which deck new cards are coming from.
Hopefully this is somewhat useful.
Feel free to ask further questions if anything is unclear.
Also note that since this is not an AnkiDroid specific question, you might be able to find additional help on
http://anki.tenderapp.com.
Flavio