Queens duel in summer

The white queen is already facing checkmate, advance only one field and the end would be sealed? No - the black queen could repel the attack, because the field c2 is covered. The two most effective figures seem to be leering at each other, who will venture out of cover first, who will launch the attack? However, one small thing is still missing to decisively influence the balance of power. A good idea is needed to win in White's favor. Good luck - you have three moves.