Where in exodus does it say God says I created pharaoh or the king with evil in his heart to fulfill my word?

There is no such verse in Exodus. According to the NIV Exhaustive Concordance compiled by Edward W Goodrick & John R. Kohlenberg III there isn't even a verse close (either in Word choice or theme) contained in Exodus. If you encountered this verse at all, it was a very bad misquotation.