Valcili's page

The best approach to this I believe is to just re-design the spell, "Magic Missile, Greater" to a higher level spell. put it into a category that would make it compete able with higher levels.
like this:
Magic Missile, Greater 5 Lvl spell - This spell functions like Magic Missile, except For every two caster levels beyond 9th you gain an additional missile to a max of 10 at lvl 19. in addition you add your Int/Cha modifier to each missle.

example a lvl 10 Sorcerer with a Cha of 18 (+4) could cast greater magic missile releasing a volley of 5 unerring missiles each doing 1d4 +4 to a single target or up to 5 separate targets no two of which can be more than 15 ft. apart with a range of medium so up to 110FT distance.

if targeted at 1 opponent 25-40 points of damage
if you were a 19th lvl wiz with Int of 25(+7) then you would bust out 10 missiles ranging from 8-11 each for a total of 80-110 to a single target. that is right on par with other spells like cone of cold which is considered weak for 5th level.

This of course would need to be approved by the GM of the House, if this is an acceptable option for the house of course. (this was just a quick make up on the spot, might need a little tweaking, but it is a good base line for a better design)