Please Help, Edit Attribute with Roll Button

I'm working on a custom sheet. I was trying to set up a roll to automatically change an attribute, in this case expend a resource. I'm terrible at coding so can't quite figure it out.  What I was doing was adding this at the end of the roll: {{@{ResourceCur}=-@{abilitycost}}} But that clearly doesn't work. Do I need to use a sheet worker or set up an intermediate attribute or something? Thanks, appreciate the help!

You can't change attributes without a sheet worker. If you want to make a roll AND change an attribute, you must use Custom Roll Parsing (a type of sheet worker). <a href="https://wiki.roll20.net/Custom_Roll_Parsing" rel="nofollow">https://wiki.roll20.net/Custom_Roll_Parsing</a> Also it must be an action button. You can't do this with a roll button.