No. I'm afraid that can't be done within the 3300.
At one time you could if you used a NSU but generally those are not in use any longer.
It may be you will have to talk with your carrier to see what can be done.
It may be possible to break your PRI's into two groups.
One DID points to group A and all the other point to a second group B.
Then the carrier can overflow Group B to Group A. (But not A to B)
This should accomplish what you're looking for.
Ralph