Aiming at the Target(Spell Compendium, p. 8)
Level: Sorcerer 2, Wizard 2, Spellthief 2,
Casting Time: 1 immediate action
Duration: Concentration, up to 20 minutes; see text
As you intone the words of power to release this spell, you feel far more focused on the spell on which you have been concentrating.
When you cast this spell, you increase your ability to concentrate on a spell you have already cast. You can cast this spell while maintaining concentration on another spell. Aiming at the target gives you a +10 circumstance bonus on Concentration checks you make to maintain concentration on the other spell, and its effect lasts as long as you concentrate on the other spell (to a maximum of 20 minutes).