I don't know how you'd manage that. I think you'd have to tape it back or something and that could cause some serious problems.
The foreskin is attached to the glans penis in the vast majority of cases so in order to do this you would have to literally rip it off.
Also, the foreskin is designed to protect the glans and keep it smooth and supple, by pulling it back or through circumcision, you'll only desensitize the penis.
I knew a guy who kept his foreskin behind his glans. I never asked him why but it always seemed odd.
In the other thread you thought that PE might only grow the penis and not the skin. I doubt that will happen as PE is designed to grow the whole thing.
I love long foreskins, so maybe I'm biased but be happy that you still have it and flaunt it, don't hide it.