Discount in percent to amount

Hi Experts.

Actually  need to know how can I mantain an amount discount instead of percent amount.It´s due to the decimals that ByD allows to type to the percent, i can´t get the gross price that i need.

For example:

I need to sell a product which list price is $12,345, but with a discount the gross price has to be $5,754, so calculating the discount in percent, it has to be 46.6099635479951%, but i can´t type this number in ByD due to the number of deimals, so it will be easy to type the amount doscount that should be $6,591.

Does anyone knows how can i do that? Or maybe another solution?

Best regards.