I have a case with a defendant on probation who continues to make payments (imagine that!). My victim died & didn't have enough assets to make a probate case worthwhile for his elderly mother. Our judge wants us to file a suit putting the money currently in the account at probation + the right to receive future restitution payments into the registry of the court and getting a court order to set out who is to receive the payments. Anyone know what kind of case I should file?

I do not believe that you have legal authority to file suit on behalf of the victim or her estate. The judge should simply conduct a hearing, hear evidence on the death, and amend the conditions of probation to have the payments go to the victim's mother. Much simpler.

Ken is right, as always. That is the way to do it. Might notify any potential heirs by posting notice of this hearing.