Noun clause as object

I know I can use a subordinate clause as an object of a sentence.

I don't know who is that person.

Can I put this object at the beginning of that sentence

who is that person, I don't know.

Answer

A poem we all learn in high school is "Stopping by Woods on a Snowy Evening," by Robert Frost. It begins:

Whose woods these are I think I know. 

It's a simple and legitimate inversion of "I think I know whose woods these are." In common speech, such inversions are used for emphasis:

Whether she's coming I can tell you, but what she'll be wearing is still a secret.

The comma is usually unnecessary. In your sample case, I suggest "Who that person is I don't know." It's an indirect question, so the interrogatory form "who is" is not correct.