I'm not sitting in front of BS, so I cannot answer that at this time. However BS Lite for Android doesn't have such a tool; it should and I will forward the suggestion.
Yet I have used an Android App in the past that will make the gravity correction for you, Brewzor Pro, but you need to know the pre- boil volume. I did some calculations for you based on some assumed volumes.
Your preboil gravity of 1058 with desired gravity of 1068:
5 g add 18.18 oz (1.10lb) of DME
6.5g add 23.64 oz (1.51 lb) of DME
8.49 g (this is my usual pre-boil volume based on loss) add 30.76oz(1.91lb)I've of DME.
I've seen the calculation in Palmer's How To Brew as well, but again don't have it in front of me.
Hope that helps. Download the app or give.me your volume and I'll plug it in for you.