ah, ddnt think of that..
well u could make it:
levels up
if level is greater than 10
if [some boolean variable(Player Number of leveling hero)] equal False
then add 1 Strength.
etc
only prob is that its going to make alot of triggers and variables. hopefully u have a reasonable level limit and it wont be too much.
Well I have quite a lot of time now but I don't have enough experience with triggers. I need more details about how to make these triggers.