I'm running into a brick wall trying to code the ED4E character sheet. We're trying to have a targetable attribute that is added together from other attributes elsewhere on the sheet. In Earthdawn, your Physical Defense (PD) starts off as a static number, but there are several things that can modify it to a particular attacker. I've set up checkboxes to represent the most common things (stances, harried, cover, blindside, etc.) and have another location to add in numerical Modifiers for the uncommon ones. So, adding the Base + Mod + Stance + Position adds up to your current PD. I have Rolls that Target PD. But, it seems that if PD is a sum, not an entry, Roll20 doesn't create an Attribute that can be targeted. From what research I've been able to do, it seems like Sheet Worker might help with this, but we haven't been able to figure that out yet.