Needs review
Source: Epic Level Handbook

Description: You can activate a staff without using a charge.

Prerequisites: Epic Level, Craft Staff, Spellcraft (15 ranks)

When you activate a staff, you can expend a spell slot instead of using a charge. The spell slot must be one you have not used for the day, though you can lose a prepared spell to emulate a staff charge (but you cannot lose prepared spells from a specialty school). The spell slot expended must be equal to or higher in level than the specific spell stored in the staff (including any level-increasing metamagic enhancements). You cannot emulate a charge for a staff power or ability that does not match a specific spell. For example, you can use this feat to lose a prepared 3rd-level spell to activate lightning bolt from a staff of power, but you can't lose a spell to double the staff's melee damage because that power doesn't match a specific spell.