Excellent question. I would also be interested in this. The only thing I can tell you is that the Divorce Remedy book talks about infidelity in a chapter, and there is a part in there about how the LBS's actions are not making any progress in working towards reconciliation due to the fact that the WAS is having an affair...not a lot you can do to improve a marriage that is literally on hold.
I take it you ask this because this is your situation, too. Do you have a thread where you have posted what's going on? If so, let me know so I can go read up.
I have scoured several bookstores looking for what you are also in need of; if you stumble upon a book that might help us, please get back to me!
Take care.
Most of us really marry only once. First love endures, even unto our dying day. And we never really divorce.