New Parameters?

[Xandhoniox]

I'm looking to add a few new parameters into my game, such that using a certain type of weapon or magic will increase the parameters associated with those weapons and magics. I know how to add words into the status screen and all that, but how exactly would I manage to actually add new parameters? By "actually," I mean this: I need these new parameters to be set to a leveling curve (or at least to a managable expression) much like the default parameters of Strength, Speed, Intelligence, and Dexterity. It seems as though it wouldn't be all that hard to figure out, but everything I've tried just falls flat. Any suggestions? Thanks in advance (I hope).