Ability with Variable + Calculated Value

[blzbob]

I need this calculation to show up in the Specials tab.

For each day spend transmuting material, the alchemist creates a volume of the material with a value in silver pieces of 1d20 + the alchemist level + the alchemist’s Intelligence modifier.

I simply want it to say 1d20 +[calculated value] sp/day.

I tried to do the Automatic Calculations but that shows a flat value instead of the 1d20+ part that I want. I also can't create a custom tag that says "sp/day." I found one for GP but not for SP and I can't use the "/" in my new tag.

Any suggestions?