First off, let me clarify that I am by no means a grammar scholar, so please excuse any mistakes I make.
My questions is with regard to the following phrase: "what the purpose will be, I don't know."
Is a coma proper here? If not, what punctuation should go here?
I realize that the sentence should be, "I don't know what the purpose will be", but for stylistic purposes I've chosen to reorder the sentence (making it passive voice, if my highschool grammar lessons are remembered correctly).
Thanks for your help.