Shortcode to create default field value

Hi,
Great plugin, this helps me a lot for what I need to accomplish. Just one question: Is there a possibility to use a shortcode in one of the form fields or to use it as part of the price calculation in the background? I’m developing a webshop for jewellery, and the current gold price needs to be added to the price calculation upon ordering the items. I can currently get the gold price through a shortcode but so far have not been able to figure out how I can make it part of the calculation.

Thank you so much for your help!

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