Improved toughness feat.

[Diceman]

Greetings,
My sunday group decided to start a 3.5 campaign with level 4 starting characters. For fun I took my friend's fighter character and attempted to recreate it using the demo version of hero lab.
One of his fighter feats was Improved toughness which grants the character +1 hit point per hit die as opposed to the toughness feat which grants a one time bonus of +3 hit points. I think there is a prerequisite of +2 con modifier as well.

This feat is not in the standard data file so we attempted to recreate it using the edit tools. I admit I am a little over my head using the editor, but we were able to figure it out EXCEPT how to make the mechanics actually grant a +1 hit point bonus per hit die. Since we were just messing around we settled for copying the standard toughness feat(renamed improved toughness) made it a fighter bonus feat, and changed the hit point bonus to 4 instead of 3 to make the print preview reflect the actual effect of the improved toughness feat on a level 4 character.

I was trying to sell my gaminig group on the idea of purchasing the d20 data package as a group by showing off the demo, but this one feat, and our inability to create it properly resulted in my players having a negative view of the program.

I tried for several hour how to code the feat properly but was unable to code the eval scripts correctly. Using the standard toughness feat as a blueprint all I could do was change the one time +3 hit point bonus to a one time +4 hit point bonus.

How would you change the following eval script to grant a +1 hit point per hit die instead?

~ If we're disabled, do nothing
doneif (tagis[Helper.FtDisable] <> 0)

container.child[Totals].field[tHP].value = container.child[Totals].field[tHP].value + 4

Any help would be appreciated.