Embedded data / javascript options with Constant sum

Hi,

For my master thesis, I am running an experiment that usually takes place physically, but due to covid it has to be online. It is an Auction which the participant plays against "the computer".
I am using Constant Sum as a bidding tool, and I was wondering if there is some code/embedded data in which I can create a starting capital that decreases with the total of the constant sum and increases with a constant price of 5 or an uncertain price of 3/5. See the screenshots.
So some code that indicates a starting capital of 15, that decreases with the bidding amount which is in total constant sum and increases with the reward if he/she won the auction which I branched with a (win) greater or equal than Price of 3 and (loss) with less than 3.
I hope someone can help me, or has a better idea to put this in qualtrics.

Daniël Bakker