Extract games while White is in wining position (+3 or more)

Hello, I have a pgn that contains many games (Not Analyzed) with common mistakes/blunders for both white and black. I want to extract White's games while it is winning position (+3 or more) and similar things to Black ( -3 or more) with diffrent pgn. Actually i want 2 different pgns (1 with white and 1 with black). I have tried to use Poly 1.7a(http://rebel13.nl/download/books.html) but i am not getting it (I am pretty sure that i am doing something wrong). Can you tell which method should i follow?
Any information regarding this will be very helpful.
Thanks.

I think the software that will do what you want is not available.

Admin wrote:

I think the software that will do what you want is not available.

Chessbase could do that if you analyze the games. And filter the games with a commentary text search like +3 or -3.