If you're wanting a spell granting extra attacks, get a hold of Battlearms from Dragon Magazine #356, pg. 48-49. Its like Girallon's Blessing + Divine Power combined into one spell, only it grants you additional attacks as well as the ability to wield weapons and attack with them. You'll want to pick up some supporting feats somehow though.
4th level cleric/blackguard spell.
EDIT: I'll throw in the spell text in case you don't have the Dragon Magazine Issue its from.
Battlearms
Evocation
Level: Cleric 4, Blackguard 4
Components: V, S, DF
Casting Time: 1 standard action
Range: Personal
Target: You
Duration 1 round/level
Calling upon the power of Hextor, you imbue yourself with skill in combat and create extra arms. Your base attack bonus becomes equal to your character level (which might give you additional attacks), you gain 1 temporary hit point per caster level, and you grow a pair of extra arms from your torso. You may use these extra arms to make unarmed strikes or wield weapons. If you use these extra limbs to attack, attacks with your primary hand are at -6, the three other hands are at -10. If you have the two-weapon fighting feat, the penalty on attacks with all of your hands drops to -4. At 12th level, you grow an additional pair of arms.
These extra arms cannot cast spells. You cannot cast a spell and make an attack with these arms in the same round. On the round you cast this spell, each new arm may draw one of your weapons as a free action. On any later round you must use a move action to equip weapons in one or more of your extra hands. The arms are a neutral gray color and barely human. They cannot hold any items other than weapons, help climb or swim, or engage in any activity other than combat.