Item creation - Creating an item that gives one spell a +1 to ranged attack and +1 to damage

My DM is giving me a magic item that boost one spell specifically, Eldritch Blast specifically, and I only want that bonus to apply to that spell on my spell list.  I know you can add a mod to an item that boost all spells with a +x, but is there a way to specify what spell gets the plus?  I would like it to be tied to the item in case something causes me to loose the item or if I am holding something else other than that one item.  I thought a global damage and attack modifier, but I could not find a way to tie it to a specific spell.  

Edit the spell directly to add the bonus?

I'm assuming you're using the 5e OGL by Roll20 sheet, but Shaped should have something similar to this: Just put a 1 in those two boxes and you are good to go.  I hope this helps ^_^

Gen Kitty said: I'm assuming you're using the 5e OGL by Roll20 sheet, but Shaped should have something similar to this: Just put a 1 in those two boxes and you are good to go.  I hope this helps ^_^ You can even just put a single '1' in the box next to MAGIC BONUS  if you want a bonus to both attack rolls and damage.

I think that is what I am going to have to do.  The only issue I see is editing it if I unattune.  But that is more of a me issue and sometimes you just have live.   Thank you both for your help.