Connect "discount" field via CMS

How can I connect an object field (discount) via CMS to a text field?

Wix Studio

What are you trying to achieve:
Show discount value (in %) as number.

What have you already tried:
Question 1:
I’ve connected several fields from WIX stores via CMS to text fields. (Formatted discount price, name, etc.) all fine. But if I try to connect the field “discount” it’s not possible for some reason. It’s defined as a Java field. I didn’t find any solution to connect that to text.

Question 2:
Furthermore Percentages are calculated automatically from WIX. E.g.:
Price: 200
Discounted price: 100
Discount: =50%

But if discounted prices are odd numbers e.g. 99.99 it seems to be impossible to show a discount in percent. Is there a workaround for these two problems?

Thanks and best regards