On your character sheet you can fully make a custom weapon, spell, or other.  I think I have it mostly worked out on how it works.  However I can't find a way to change the + to hit.  I can add a + to damage but not + to hit.  What am I missing?  I'm not talking about modifying an existing weapon.  I'm talking about the fully custom option.

If your talking about making a +1 weapon then you select bonus "magic" and then it will give you the +1 +2 ect. Modifiers. 

Hope that's what you meant