Stat Distribution

I can't figure out how to make this but I want to allow me or another player to decide stats instead of gaining every level. like hero gains a level and he gets 6 attribute points to spend on stats.|||Give the player 6 lumber and make a shop that sells tomes for 1 lumber? Other then that I can't think of any other way, unless you make their spells in a spellbook and their hero spells are arttibute abilities.|||This would be annoying to trigger, but here it goes.

When unit gains a level (there's an event for this) you do two things. 1) give him three abilities: raise agil, raise str, raise int. 2) increase the variable STAT by 6. Each time the hero uses one of those three abilities (there's an event for this too), you decrease his STAT variable by one. If STAT is zero, then remove those three abilities.

You could put those three abilities in a spellbook in order to keep things tidy. Also remember to set each hero's natural stat increase per level to 0.