A crushing 10-wicket win at Trent Bridge on Wednesday has left the NatWest Series level at 2-2 with one match to play - and Cook believes England can complete the comeback in the fifth and final fixture.
The 26-year-old told Sky Sports News: "We've got a final. We fought back well at Trent Bridge and I'm excited to be able to beat Sri Lanka over a five-match series.
"It was a great team performance. We put them under pressure when we bowled and to knock the runs off like that doesn't happen very often. It was very rewarding.
"We've put ourselves in a good position and the lads are really looking forward to it."
Cook led by example on Wednesday with an unbeaten 95 but he said: "It's about the team. My job is to get runs and I feel like I'm in form.
"But the art of leadership is picking the right side for the right conditions. We'll try to pick the best side we've got for the wicket. We will have a look at it and try to make the decision tomorrow morning."
(reopens) Sri Lanka are expected to replace the injured Suranga Lakmal with fellow seamer Dhammika Prasad tomorrow.
Lakmal will be out for a month after suffering a side strain at Trent Bridge.