How important is it to the player to use his current weapon? Instead of a dwarven longhammer, can I offer the dwarven longish hammer?
Using weapon design rules from Weapon Master's Handbook, building for an exotic two handed melee weapon, we can get the maximum number of build points (6 for exotic, 3 for 2-handed, 3 from claiming additional design points). With this, building it to be as close to the long hammer as we can while giving him close range options, we can completely recreate the long hammer while also allowing him to switch between reach and close as a swift action (improved damage x5 (5pts), improved critical multiplier x1 (3pts), spring loaded (2 pts), weapon feature: reach (1pt), Traditional (1pt)).
Congratulations, he now has swift action reach with no feat expenditure.